Methods and devices for  reducing gastric volume

ABSTRACT

The present invention involves new interventional methods and devices for reducing gastric volume, and thereby treating obesity. The procedures are generally performed laparoscopically and may generally be described as laparoscopic plication gastroplasty (LPG) in which, after obtaining abdominal access, spaced apart sites on a gastric wall are engaged and approximated to create one or more tissue folds that are then secured by placing one or more tissue fasteners to produce one or more plications projecting into the gastrointestinal space. The serosal tissue may optionally be treated during the procedure to promote the formation of a strong serosa-to-serosa bond that ensures the long-term stability of the tissue plication. These procedures are preferably carried out entirely extragastrically (i.e. without penetrating through the gastrointestinal wall), thereby minimizing the risks of serious complications. Minimally invasive devices for approximating and fastening soft tissues are disclosed that enable these new interventional methods to be carried out safely, efficiently and quickly. Methods for reversing the procedure are also disclosed.

REFERENCE TO PRIORITY APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/184,173 filed Jul. 31, 2008, which is a continuation-in-part of U.S.patent application Ser. No. 12/048,206, filed Mar. 13, 2008, whichissued as U.S. Pat. No. 8,142,450 on Mar. 27, 2012 and claims priorityto U.S. Provisional Patent Application Nos. 60/894,626 filed Mar. 13,2007, 60/952,871 filed Jul. 31, 2007, and 60/990,968 filed Nov. 29,2007. U.S. patent application Ser. No. 12/184,173 also claims priorityto U.S. International Patent Application No. PCT/US08/56921 filed Mar.13, 2008. These patent applications are incorporated herein by referencein their entireties.

FIELD OF THE INVENTION

The present invention relates generally to methods and devices forreducing the volume of a hollow body organ, such as gastric volume. Oneapplication of methods and devices of the present invention is treatingobesity in a patient by effectively reducing the functional volume ofthe stomach.

BACKGROUND AND DESCRIPTION OF THE PRIOR ART

Obesity is rapidly reaching epidemic proportions in developed societiesworldwide. There are currently over 1 billion overweight peopleglobally, with 300 million of these people considered clinically obese.In the United States alone there are more than 50 million obese adults,and the numbers are expected to increase by more than 50% in the nextdecade. Morbid obesity (i.e. obesity in which there are secondarycomplications such as hypertension, diabetes, coronary artery disease,stroke, congestive heart failure, orthopedic problems and pulmonaryinsufficiency) not only affects quality of life, but also shortens lifeexpectancy and costs the health care industry billions of dollarsannually.

Interventional procedures and associated medical devices for treatingmorbid obesity in patients are well known in the art. In general, theseinterventional procedures promote weight loss by either (a) gastricrestriction or volume reduction, (b) malabsorption, or (c) a combinationof the foregoing. Gastric restriction or volume reduction methodspromote weight loss by limiting the amount of food intake (i.e. thepatient eats less), either due to physical space limitation or byinducing a feeling of early satiety in the patient. Malabsorptionmethods promote weight loss by limiting the uptake of nutrients (i.e.the patient digests less of what is eaten), usually by removing orbypassing a portion of the gastrointestinal (GI) tract.

Among the earliest interventional procedures directed at promotingweight loss were variations of the jejuno-ileal bypass developed in the1950s. This surgery effectively bypasses the small intestine and istherefore a strictly malabsorption procedure, which poses serious risks.The bilopancreatic diversion procedure, which combines bypass of most ofthe small intestine with a partial gastrectomy, is a combined volumereduction and malabsorption procedure that was developed in effort toreduce these risks, but it too had complications and its success waslimited.

Roux-en-Y gastric bypass surgery is a commonly performed bariatricprocedure, especially in the US. It was originally performed as an openinterventional procedure, but it is now routinely performedlaparoscopically. This procedure utilizes interventional stapling andcutting devices to form a small stomach pouch, bypassing the lower partof the stomach, and creates a Roux-en-Y limb to attach the jejunum tothe pouch. The Roux-en-Y procedure is predominantly a volume reductionmethod (the stomach pouch is typically ˜25 cc in volume), although thereis a significant malabsorption component.

Despite the proven efficacy of the Roux-en-Y procedure in terms ofachieving weight loss, and the recent laparoscopic improvements thathave reduced the associated interventional risks, it remains a highlyinvasive procedure with substantial rates of morbidity. The rate ofinterventional mortality may be as high as 1%, and known complicationsinclude frequent pulmonary morbidity and anastomotic leaks that can belife threatening. Furthermore, the malabsorption component of theRoux-en-Y procedure can negatively affect health because of reducedvitamin uptake, and the long-term consequences of malabsorption are notyet fully understood.

A variety of other interventional procedures have also been developedinvolving the use of interventional stapling to bring together andfasten opposing walls of the stomach in order to reduce its volume. Mostinvolve malabsorption to a greater or lesser extent, depending on theprocedure. Examples of such procedures include the horizontalgastroplasty (HG) and vertical banded gastroplasty (VBG), as well asmore recent variations such as the Magenstrasse and Mill (M&M) andlaparoscopic sleeve gastrectomy (LSG) procedures that involve not onlystapling, but cutting away and removal of the unused stomach portion,leaving behind a reduced volume tube or sleeve running more or lessparallel to the lesser curvature between the esophagus and the pylorus.Surgically inserted artificial sleeves that longitudinally traverse thestomach may achieve similar effective volume reductions whilesignificantly increasing malabsorption. In any case, weight loss resultsachieved with these procedures may sometimes approach those of theRoux-en-Y, however these procedures are not easily performed, aredifficult if not impossible to reverse, and still suffer from risks ofserious complications, most frequently related to failure or leakage ofthe staples, which can lead to dangerous infections and even death.

An alternative minimally invasive procedure recently growing inpopularity involves the laparoscopic placement of an adjustable siliconering around the upper portion of the stomach, thereby creating a small(e.g. 50-120 cc) pouch. The LAP-BAND® is one such commercially availablerestrictive device that, after placement, induces a feeling of earlysatiety in the patient. Although considerably less invasive than theRoux-en-Y procedure, and potentially reversible, significantly lessweight loss has been observed with laparoscopic banding. This procedurealso suffers from a variety of limitations and shortcomings. Forexample, because the laparoscopic band does not actually reduce thevolume of the stomach, some patients report a feeling of nearly constanthunger. Additionally, long-term complications of the laparoscopicbanding procedure may include tissue erosion, slippage of the band,infection, or lack of effectiveness, frequently requiring removal of theband after a period of time.

Another less invasive alternative to the above-mentioned procedures isthe intragastric balloon. The intragastric balloon is an inflatabledevice that is deployed within the stomach, thereby displacing a knowninternal volume. The advantages of this method are that it is minimallyinvasive, involves no malabsorption component, and requires no stapling,permanent reconfiguration or removal of tissue. While the correlationbetween apparent stomach volume reduction and weight loss is wellestablished by the intragastric balloon method, the weight loss achievedis typically considerably less than with Roux-en-Y. Furthermore, unlessit is surgically fastened to the stomach wall, the balloon is freefloating and frequent complications such as obstruction, mucosalerosion, nausea, vomiting and pain have been documented, with the resultthat intragastric balloons are usually removed within 6 months afterinitial placement.

In effort to develop even less invasive devices and procedures, morerecently there has been considerable interest in various transoral (ortransesophageal) endoscopic approaches for reducing stomach volumeentirely from within the gastrointestinal lumen, without the need forabdominal incisions. In general, these approaches involve advancing anendoscope down the patient's esophagus and into the stomach, wherebyvarious tools are then used to manipulate and reconfigure the stomachtissue in order to create one or more divisions or internal folds (alsoknown as plications) within the stomach wall. To securely hold thedivisions or plications so formed, some form of sutures, staples,anchors, or other similar securing means are placed transesophageallythrough the stomach walls, and sophisticated endoscopic tools have beendeveloped for such purposes. Tissue approximation and fixation devicesfor use in endoscopic procedures are described, for example, in U.S.Patent Publications 2004/0215216, 2007/0112364, 2005/0080438. Many othertypes of endoscopic tissue approximation and fixation devices andfasteners are also known in the art.

While quite promising, endoscopic approaches for reducing stomach havevarious limitations and shortcomings. For example, they must beperformed by highly skilled endoscopic surgeons and involve the use oflarge, complicated endoscopic devices that require specialized trainingto deal with the restricted access and small working space. In order toaccess the stomach internally, devices must be passed down the patient'sesophagus, accruing a substantial risk of perforating the esophagus andinjuring adjacent organs. In addition, capturing and manipulating thetissue layers and accurately applying the securing means during atransesophageal procedure is not only difficult but also hazardous, dueto the significant risk of accidental injury to other organs, bleeding,etc., when piercing (intentionally or accidentally) the stomach wall.Because there is no extragastric visualization in these procedures,there is no advance warning of a developing life threatening situationthat may require a rescue operation.

The stomach wall is comprised of four main tissue layers. The mucosallayer is the innermost tissue layer, adjacent a submucosal connectivetissue layer. The submucosal connective tissue layer interfaces with themuscularis layer, and the serosal layer covers the exterior(extragastric) surface. Prior art gastric reduction procedures involvingtissue reconfiguration from inside the stomach require the placement ofsutures, staples, or anchors during surgery to hold the reconfiguredtissue in place strongly enough to sustain the tensile loads imposed bynormal movement of the stomach wall during ingestion and processing offood. Because the mucosal and submucosal connective tissue layers arerelatively weak and prone to elastic stretching during digestion, thesecuring means generally penetrate the stomach wall to engage at leastthe muscularis layer. For this reason, the prior art securing means aregenerally transgastric, passing one or more times completely through thestomach wall.

Proper use and placement of fasteners that penetrate the gastric wall ischallenging and concentrates significant forces over a small surfacearea of mucosal tissue, thereby potentially causing the suture, stapleor anchor to leak or tear through the tissue, with potentiallydisastrous consequences. It is well known that the fasteners used inthese procedures frequently migrate, dislodge or even completelydisappear over time, resulting in partial or complete failure tomaintain the gastrointestinal volume reduction, as well as possiblecomplications. These are significant limitations and shortcomings ofprior art bariatric procedures involving tissue reconfiguration.

Previously known interventional procedures for treating obesity throughgastrointestinal volume reduction or malabsorption thus involve numerousrisks, including life-threatening post-operative complications (e.g.internal bleeding, infection), and long-term problems such as diarrhea,vitamin deficiency, electrolytic imbalance, unpredictable orinsufficient weight loss, and gastrointestinal reflux disease (GERD).Given the above noted shortcomings, limitations and risks of prior artprocedures, it is apparent there remains a need for safe,easy-to-perform and effective interventional procedures for reducinggastric volume, as well as for devices enabling such procedures.

SUMMARY OF THE INVENTION

The methods and devices of the present invention represent a newapproach for reducing gastric volume, and thereby treating obesity andother disorders of the gastrointestinal tract, that is safe, effective,and overcomes many shortcomings and limitations of prior art procedures.In general, methods of the present invention involve reconfiguring aportion of the gastrointestinal tract (e.g., stomach wall) from theabdominal space, by contacting external tissue surfaces and drawing themtoward one another to form one or more tissue invaginations, thenapproximating the shoulders of the extragastric tissue forming theinvagination to form a tissue fold or plication and then securing theshoulders of the extragastric tissue forming the plication to maintain apermanent plication. In preferred embodiments, the extragastric tissueis approximated such that external tissue surfaces abut one another toform the tissue plication, which extends into the internal gastricspace. One or more plications may be formed to effectively reduce thecircumference, and thereby cross-sectional area and volume, of thegastrointestinal lumen. One of the advantages of this procedure is thatthe gastric volume is reduced without reducing the mucosal surface areainvolved in digestive absorption. In a preferred embodiment of thepresent invention, the portion of the gastric tissue that isreconfigured, according to the procedure described above, is theanterior surface or anterior wall of the stomach, which is readilyaccessible from the intra-abdominal space. In another preferredembodiment of the present invention, which may allow for even greatergastric volume reduction, the portion of the gastric tissue that isreconfigured includes both the anterior surface and posterior surface ofthe stomach.

The methods of the present invention may be carried out using openinterventional procedures, which are useful, for example, to penetratethe abdominal space and obtain access to difficult or remote regions ofthe abdomen and gastrointestinal tract, such as the stomach.Alternatively, however, abdominal access to the gastrointestinal tract(e.g., stomach) is provided using conventional laparoscopic proceduresthat involve relatively minimal penetration of the abdominal space.Minimally invasive non-laparoscopic methods may also be used (i.e.wherein access to the abdominal cavity is achieved without establishinga pneumoperitoneum via insufflation) to access the external surface(s)of the gastrointestinal tract. Numerous methods for accessing theinternal abdominal space, and for monitoring intra-abdominalinterventions (e.g., imaging and visualizing the intra-abdominal spaceand intervention) are known and may be used in conjunction with methodsof the present invention.

According to one embodiment of the present invention, a method forreducing gastric volume comprises obtaining access to an externalsurface of the gastrointestinal tract (e.g. stomach); invaginating andapproximating the wall of the gastrointestinal tract from its externalsurface to create at least one plication therein; and fastening surfacesof the approximated gastrointestinal wall to one another to secure theplication(s). According to another embodiment, a method for reducinggastric volume comprises obtaining access to an external surface of thegastrointestinal tract (e.g., stomach); invaginating and approximatingthe wall of the gastrointestinal tract from its external surface bydrawing external surfaces of the gastrointestinal tract toward oneanother to form a plication extending into the interior space of thegastrointestinal tract; and fastening the approximated surfaces of thegastrointestinal wall to one another to secure the plication(s). Thismethodology provides a significant reduction in the internal volume ofthe gastrointestinal tract (e.g., stomach) without reducing the interiorwall surface available for digestion and nutrient absorption.

The exterior serosal layer and adjacent muscularis layers of thegastrointestinal tract have relatively more strength than the submucosaland mucosal layers. In certain embodiments of methods of the presentinvention wherein external surfaces of the gastrointestinal wall areapproximated to form a plication projecting into the internal space ofthe gastrointestinal tract, fastening of the approximated portions ofthe gastrointestinal wall is accomplished by penetrating fewer than allof the layers of the gastric wall. In preferred embodiments, fasteningof the approximated portions of the gastric wall is accomplished bypenetrating at least the thin, tough serosal layer covering the exteriorof the gastrointestinal lumen and, optionally, the serosal andmuscularis layers, without penetrating the submucosal and mucosal layersof the gastric wall. In these embodiments, the intragastric space is notbreached during the procedure, and the mucosal layer of thegastrointestinal tract remains intact. This is advantageous not onlybecause it simplifies the procedure, but also because it avoids avariety of known complications arising from prior art procedures thatmay result when transgastric methods are employed that puncture, damageor otherwise compromise the mucosa during the intervention. Thus,according to another embodiment, a method for reducing gastric volumecomprises obtaining access to an external surface of thegastrointestinal tract (e.g. stomach); invaginating and approximatingthe wall of the gastrointestinal tract from its external surface to forma plication extending into the interior space of the gastrointestinaltract; and fastening approximated surfaces of the gastrointestinal wallto one another without penetrating all layers of the gastric wall tosecure the plication(s). In one embodiment, the surfaces of thegastrointestinal wall are fastened to one another using fasteners thatpenetrate at least the serosal layer, and preferably the serosal andmuscularis layers of portions of the gastrointestinal wall forming theplication.

Additional embodiments of methods of the present invention, disclosed indetail below, incorporate additional features for the purpose ofimproving the safety and effectiveness and/or reducing the complexityand cost of the procedure. For example, in one embodiment of methods ofthe present invention, immediately prior to, or contemporaneously withthe above mentioned invaginating and approximating steps, serosal tissueon surfaces of the gastrointestinal wall that adjoin to form theplication is treated to promote bonding or adhesion of adjoining tissuelayers within the plication. In one embodiment, bonding of adjoiningtissue layers within the plication is accomplished by disrupting theserosal tissue and promoting a healing response therein. In onepreferred embodiment, a serosal tissue treatment that involves serosaltissue disruption and/or promotion of the formation of aserosal-to-serosal bond is provided over substantially thegastrointestinal surface area involved in forming the one or more tissuefolds.

It is known that serosal tissue is capable forming strong adhesions toitself, or adjacent tissues, following inadvertent disruption of ordamage to the serosal tissue that occurs during surgery. Typically, suchadhesions are considered an undesirable and sometimes dangerouscomplication of abdominal surgery, and avoiding inadvertent damage tothe serosa to minimize the formation of adhesions is an important goalduring abdominal interventions. In contrast, in methods of the presentinvention, serosal tissue disruption and formation of the consequentadhesions may be optionally and intentionally promoted on targetedsurface areas of the gastrointestinal lumen. When combined with theinvaginating and approximating methods of the present invention, it hasunexpectedly been discovered that serosal adhesions can be usedbeneficially for the purpose of providing a supplementary or evenprimary securing means for the gastrointestinal reconfiguration.According to the present invention therefore, serosal tissue on surfacesof the gastrointestinal wall that form the plication may be treated todisrupt the serosal tissue and promote a healing response for thepurpose of selectively promoting the formation of a serosa-to-serosabond across the approximated tissue boundary within the gastrointestinalplication.

A strong serosa-to-serosa bond is typically formed after a relativelybrief period of time (e.g. approximately 7 days after surgery). Onceformed, this serosa-to-serosa bond is sufficiently strong tosubstantially resist the separation forces generated by the stomachduring ingestion and digestion, and ensures the long-term integrity ofthe plication. The formation of a strong serosa-to-serosa bond in thegastric plication of the present invention significantly improves thedurability and lifespan of the plication, and consequently of thegastric reduction, and offers a significant improvement compared to the(solely) mechanical fastening methods used in tissue approximation andplication in the prior art. Thus, in the present invention, thefasteners used during the intervention to initially secure the tissuefold serve as the sole structural support for securing the plicationonly during the brief healing phase following surgery. Following itsformation, the serosa-to-serosa bond may provide the primary structuralsupport for securing the plication, and the fasteners initially placedto secure the plication may be removed, absorbed or, more typically,left in place within the patient to provide additional support for theplication.

In contrast to Roux-en-Y or other gastrectomy procedures involvingstapling, it should be pointed out that the method of the presentinvention does not require cutting, transection, anastomosis, or removalof any gastrointestinal tissues from the body. It is therefore possiblethat the gastric reduction accomplished during this procedure isinterventionally reversible. For example, if at a later date thesurgeon/patient elects to reverse the gastric reduction, it is possibleto substantially restore the original gastrointestinal configurationusing a simple and safe procedure wherein the plication is substantiallyeliminated by removal of any remaining implanted securing means,followed by dissection of the serosa-to-serosa bond along the originalline of tissue approximation, and subsequent localized treatment toprevent further formation of adhesions during post-operative healing.

A variety of novel devices, tools and systems are provided herein thatenable a medical professional to engage and approximate soft bodytissues during an interventional procedure, more safely and convenientlythan possible using the prior art instruments. These inventive devices,tools and systems are useful for, among a variety of other possibleinterventional purposes, performing gastric reduction procedures byinvaginating and approximating the wall of the gastrointestinal tractfrom its external surface to create at least one plication therein; andfastening surfaces of the approximated gastrointestinal wall to oneanother to secure the plication(s).

Gastric reduction methods of the present invention are performed in theabdominal cavity and involve contacting and manipulating thegastrointestinal tract from its external surface. The methods aretypically accomplished using minimally invasive laparoscopic techniques,and the devices and systems of the present invention are thereforegenerally intended to be used in connection with laparoscopictechniques. However, any technique that provides access to theintra-abdominal space and, particularly, the exterior surface of thegastrointestinal tract may be used, including natural orificetransluminal endoscopic surgery (NOTES) techniques and other minimallyinvasive non-laparoscopic techniques. For example, smaller diameter,flexible embodiments of the tissue approximation and fastening devicesdescribed in detail below can be deployed through a flexible endoscopethat may be inserted into the patient's gastrointestinal tract orally,anally or vaginally, after which access to the intra-abdominal spaceand, particularly, the exterior surface of the gastrointestinal tractmay be obtained transluminally. Such flexible, endoscopic tissueapproximation and fastening devices are considered within the scope ofthe present invention.

In one embodiment, a specialized device is provided for carrying out thetissue invagination and approximation steps; another device mayoptionally be provided for disrupting and/or promoting the bonding ofserosal tissue, and yet another device may be provided for securing thetissue plication(s). A device for invaginating and approximating gastrictissue of the present invention preferably comprises a tool having anactuation mechanism (generally on or in proximity to a handle)manipulable by an operator, at least one extendible member, and at leasttwo tissue engagement mechanisms. Tissue engagement mechanisms aregenerally provided at or in proximity to the distal end(s) of the deviceor extendible member(s), but may be provided at other locations. In oneembodiment, the approximation device comprises at least one tissueengagement mechanism provided in association with a device shaft that isinserted at the site of the intervention, and another tissue engagementmechanism provided in association with an extendible member. In thisembodiment, tissue is approximated by engaging tissue at two spacedapart locations using the tissue engagement mechanisms and then movingthe extendible member and the device shaft relative to one another toapproximate the engaged tissue.

According to another embodiment, the approximation device of the presentinvention comprises at least one tissue engagement mechanism provided inassociation with each of at least two extendible members. The extendiblemembers are adjustable by the operator between an insertion (collapsed,pre-deployed) condition, in which they may be inserted into theabdominal space, and an expanded (extended, deployed) condition, inwhich the associated tissue engagement mechanisms are separated andpositioned to engage two portions of tissue spaced apart from oneanother. The extendible member(s) are also adjustable by the operator,by means of an actuation mechanism, following engagement of the twoportions of tissue to draw together, or approximate, the two portions oftissue engaged by the tissue engagement mechanisms. The tissueengagement mechanisms are furthermore manipulable to release engagedtissue, and the extendible members are manipulable to reposition themembers in a low profile, collapsed condition for withdrawal of thedevice from the abdominal space. Thus, in operation, the distal portionof the tissue invagination and approximation device is positioned in theabdominal space; a control feature is actuated by the operator to adjustthe extendible members from a low-profile, collapsed condition to adesired extended condition; and the tissue engagement mechanisms arepositioned to engage the exterior surface of spaced-apart portions ofthe gastrointestinal tract (e.g., stomach); a control feature isactuated by the operator to draw the tissue engagement mechanismstogether and approximate the two engaged portions of tissue; theengagement mechanisms are disengaged from the tissue; and afterrepeating the above steps any desired number of times, the extendiblemembers are collapsed and the device is withdrawn from the abdominalcavity.

In one embodiment, the device for invaginating and approximatinggastrointestinal tissue has a selection feature that allows the medicalprofessional to select the degree of separation of the extendiblemembers in the expanded condition, and thereby select and controlplacement of the tissue engagement mechanisms and the overall size ofthe one or more tissue folds to provide a desired degree of gastricreduction. In another embodiment, a variety of interchangeable tools maybe provided, allowing the operator to select approximation toolsproviding the desired placement of tissue engagement mechanisms and,consequently, the overall size of the tissue fold(s).

Another tissue invagination and approximation device of the presentinvention comprises a tool having at least two extendible membersadjustable between a collapsed insertion condition and an extendedoperating condition, and additionally comprising at least one tissueinvagination structure arranged and adjustable along an axis to contactand invaginate tissue located generally at a midline between the tissueportions engaged by the tissue engagement mechanisms. The tissueinvagination structure is preferably axially adjustable between awithdrawn insertion condition in which it does not extend substantiallybeyond the terminal ends of the extendible members and an invaginating,projected condition, in which the tissue invagination structure projectstoward the midline of the tissue surface engaged by the tissueengagement mechanisms. In one embodiment, the axial movement of thetissue invagination structure may be coordinated with the extension ofthe tissue engagement mechanisms such that, following engagement of twospaced apart portions of tissue, the tissue invagination structure isextended to contact and invaginate tissue as the approximation membersare drawn together to approximate the two spaced apart tissue portions.A selection feature may allow the medical professional to select thedegree of extension of the invagination structure, thereby controllingthe overall size of the tissue invagination and plication, and providinga desired degree of gastric reduction.

In yet another embodiment, a serosal treatment device may be providedand used separately from or in coordination with the tissueapproximation and invagination device. A serosal tissue treatmentdevice, in one embodiment, is adapted to disrupt serosal tissue lyingbetween spaced apart tissue surfaces engaged by the approximatingmembers to promote healing and formation of a serosal-to-serosal bondbetween serosal tissue surfaces contacting one another in the plicationformed during the tissue approximation. The serosal treatment device mayutilize one or more mechanical structures, such as a discontinuous or anon-smooth surface structure, to disrupt serosal tissue and therebypromote serosal tissue adhesion. Additionally or alternatively, theserosal treatment device may be operated to facilitate application oradministration of an agent that promotes serosal tissue disruptionand/or healing in serosal-to-serosal bonds, or to administer a tissuebonding agent that promotes serosal-to-serosal tissue bonds. The serosaltreatment device may incorporate an alternative modality for serosaltissue treatment, e.g., by application of heat, RF radiation,ultrasound, electromagnetic radiation, or other types of radiatingenergy. In one embodiment, the serosal tissue treatment device may beintegrated with the approximating members and/or the tissue invaginationstructure, as described more fully below.

A separate tissue securing or fastening device may be provided forfastening the two adjacent portions of approximated tissue to oneanother to secure the plication. Suitable devices, such as suturing,stapling and other types of mechanical tissue fastening devices are wellknown in the art. The tissue fastening device, in one embodiment, is amulti-fire device that is capable of administering multiple fasteners,in multiple positions along a line of approximated tissue, withoutrequiring removal from the abdominal space. Various types of fastenersand fastening devices may be used, as described more fully below.

In another embodiment, an integrated device may be provided for carryingout the tissue invagination and approximation steps, and for optionallytreating serosal tissue in the invaginated tissue, while a separatedevice may be provided for securing the tissue plication. Thisbeneficially eliminates the need for at least one laparoscopic incisionand trocar during the procedure. In yet another embodiment, a singlemulti-functional device is provided that comprises tools capable ofinvaginating and approximating tissue, optionally treating the serosaltissue to promote a healing response, and for securing the tissue foldto produce the plication. In this embodiment, a single minimallyinvasive laparoscopic device is provided, thereby minimizing the numberof trocars needed to complete the procedure. For example, assuming oneaccess port is needed for the video camera and one is needed for agrasper, liver/organ manipulator, dissector, or other tissuemanipulation device, the procedure may be completed using only 3trocars. In another embodiment, the single integrated minimally invasivelaparoscopic device may be optionally configured having one or moreextra service channels through which the camera and other tissuemanipulation devices may be inserted, thereby allowing the entiregastric reduction intervention to be completed using only a singleaccess port. In comparison, 5 or more laparoscopic incisions arecommonly needed for the Roux-en-Y procedure. Using a multifunctionaltool of the present invention, the gastric reduction procedure is lessinvasive, requires less time to complete and therefore reduces the risksattendant any intervention, speeds patient recovery, and reduces theoverall cost of treatment.

Other embodiments of medical devices of the present invention furtherincorporate novel tool configurations detailed below, that enable andsimplify the steps of securing the one or more tissue folds created inorder to produce the one or more plications in the wall of thegastrointestinal tract. In one embodiment, means are provided fordelivering individual tissue anchors comprising a securing assembly. Inyet another embodiment, individual tissue anchors are reconfigured froma first state (e.g. a configuration used for delivery) to a second state(e.g. a deployed configuration). In yet another embodiment, the deployedsecuring assembly is configured to penetrate only the serosal andmuscularis tissue layers, without penetrating completely through thewall of the gastrointestinal tract.

According to the brief summary provided above, it is apparent thatmethods and devices of the present invention offer several advantagesover the prior art. For example, because the one or more gastric tissueplications produced may achieve substantial therapeutic gastricreductions, it is possible to obtain weight loss results comparable toprior art procedures using an interventional alternative that may beperformed using minimally invasive laparoscopic or non-laparoscopicabdominal access procedures, while at the same time avoiding a varietyof complications associated with malabsorption, the long-term presenceof restrictive devices within the body, leakage or failure attransgastric anastomosis or anchoring sites, permanent restructuring ofthe gastrointestinal tract, and the like. Gastric reduction proceduresof the present invention are therefore simpler, easier to perform, andsafer that prior art interventional methods. In addition, the methods ofthe present invention, which may optionally be performed substantiallyor entirely extragastrically, may be carried out by conventionallyskilled laparoscopic surgeons, requiring minimal specialized training toachieve substantial gastric volume reduction and effective weight lossresults, while significantly reducing the risk of injury or damage toneighboring organs and other complications. This is a significantadvantage compared to prior art transesophageal endoluminalinterventional methods.

While the present invention will be described more fully hereinafterwith reference to the accompanying drawings, in which particularembodiments are shown and explained, it is to be understood that personsskilled in the art may modify the embodiments herein described whileachieving the same methods, functions and results. Accordingly, thedescriptions that follow are to be understood as illustrative andexemplary of specific structures, aspects and features within the broadscope of the present invention and not as limiting of such broad scope.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A-1B2 schematically illustrates an interventional method accordingto one embodiment of the present invention, wherein FIGS. 1A-1A3 showsthe pre-procedure tissue configuration; and FIGS. 1B-1B2 shows the postprocedure tissue configuration.

FIGS. 2A-2E2 schematically illustrate an exemplary interventionalgastric reduction method according to one embodiment of the presentinvention.

FIGS. 3A and 3B show an organ having a plication and a cross sectionalview of a plication, illustrating securing means applied according toone embodiment of the present invention.

FIGS. 4A and 4B show an organ having two plications and a crosssectional view of the multiple plications according to one embodiment ofthe present invention.

FIGS. 5A-5F illustrate operation of a medical device according to oneembodiment of the present invention, wherein FIG. 5A shows an overview;FIG. 5B shows a close-up, distal end of the device in a collapsed state;FIG. 5C shows a close-up, distal end of the device in an extended state;FIG. 5D shows the device in an extended state following tissueengagement; FIG. 5E illustrates partial retraction of the extendiblemembers and tissue engagement mechanisms and actuation of a projectingserosal tissue treatment member during invagination and approximation;and FIG. 5F illustrates complete retraction of the extendible membersand full extension of the projecting serosal tissue treatment member toform the plication.

FIGS. 6A-6D illustrate a medical device system according to oneembodiment of the present invention, wherein FIG. 6A shows separatetools positioning; FIG. 6B shows the tissue fold created; FIG. 6C showsthe fasteners applied; and FIG. 6D shows a plurality of fasteners.

FIGS. 7A-7H illustrate a medical device according to one embodiment ofthe present invention, wherein FIG. 7A shows an overview; FIG. 7B showsthe distal end in collapsed state; FIG. 7C shows the distal end inexpanded state; FIG. 7D shows the tissue engagement;

FIG. 7E shows the tissue invagination and approximation; FIG. 7F showsthe tissue fold created; FIG. 7G shows the securing means applied, withthe distal end retracted to collapsed state; and FIG. 7H shows aplurality of securing means.

FIGS. 8A-8B illustrate a device for approximating tissue according toone embodiment of the present invention, wherein FIG. 8A shows thepre-deployed configuration and FIG. 8B shows the deployed configuration.

FIGS. 9A and 9B show a cross sectional view of the proximal end of adevice for approximating tissue according to one embodiment of thepresent invention, wherein FIG. 9A shows the pre-deployed configurationand FIG. 9B shows the deployed configuration.

FIG. 10 shows a cross sectional view of a portion of a device forapproximating tissue according to one embodiment of the presentinvention.

FIGS. 11A and 11B show a cross sectional view of the distal end of adevice for approximating tissue according to one embodiment of thepresent invention, wherein FIG. 11A shows the pre-deployed configurationand FIG. 11B shows the deployed configuration.

FIGS. 12A-12C illustrate operation of a device for approximating tissueaccording to one embodiment of the present invention, wherein FIG. 12Ashows close-up views of the proximal and distal ends in the deployedconfiguration and engaging tissue; FIG. 12B shows partial retraction ofthe device to approximate tissue and create an invaginated tissue fold;and FIG. 12C shows complete retraction of the device, completeinvaginated tissue fold created.

FIG. 13 illustrates a tissue fastener according to one embodiment of thepresent invention.

FIG. 14 illustrates placement of an extragastric tissue fastener tosecure a tissue fold and produce a plication according to one embodimentof the present invention.

FIGS. 15A and 15B illustrate alternative embodiments for tissuefasteners of the 30 present invention.

FIGS. 16A-16C illustrate alternative embodiments for tissue fasteners ofthe present invention.

FIG. 17 illustrates an alternative embodiment for a tissue fastener ofthe present invention.

FIGS. 18A and 18B illustrate alternative embodiments for tissuefasteners of the present invention.

FIG. 19 illustrates a fastener applicator according to one embodiment ofthe present invention.

FIGS. 20A and 20B show cross sectional views of a fastener applicatoraccording to one embodiment of the present invention, wherein FIG. 20Ashows the proximal end; and FIG. 20B shows the distal end.

FIGS. 21A-21E show cross sectional views of the distal end a fastenerapplicator according to one embodiment of the present inventionillustrating the firing sequence, wherein FIG. 21A shows the pre-firedconfiguration; FIG. 21B shows the trigger retracted with the fastenerbeing loaded; FIG. 21C shows the device fully cocked and ready to fire;FIG. 21D shows the device firing with the fastener being propelled outof device; and FIG. 21E shows the firing complete with the fastenerpropelled beyond the distal end of the device, and device returned toits pre-fired configuration.

FIGS. 22A-22C illustrate the combined operation of a device forapproximating 20 tissue and a fastener applicator according to oneembodiment of the present invention, wherein FIG. 22A shows the deviceinvaginating tissue, immediately prior to tissue engagement; FIG. 22Bshows a close up of the distal end of the devices after tissueengagement and during creation of an invaginated tissue fold; and FIG.22C shows multiple fasteners inserted to secure the tissue fold, therebyproducing a plication.

FIGS. 23A-23D show cross sectional views of the distal end of a tissueapproximating device that articulates by pivot means, wherein FIG. 23Ashows the linear, retracted configuration; FIG. 23B shows the lineardeployed configuration; FIG. 23C shows the bent, retractedconfiguration; and FIG. 23D shows the bent, deployed configuration.

FIGS. 24A and 24B illustrate the distal end of a tissue approximatingdevice that articulates by flexible member means, wherein FIG. 24A showsthe linear, retracted configuration; and FIG. 24B shows the bent,deployed configuration.

FIGS. 25A and 25B illustrate the distal end of an alternative tissueapproximating device that articulates by flexible member means, whereinFIG. 25A shows the linear, retracted configuration; and FIG. 25B showsthe bent, deployed configuration.

FIGS. 26A and 26B illustrate an embodiment of a fastener of the presentinvention, wherein FIG. 26A shows the deployed configuration; and FIG.26B shows the predeployed configuration.

FIGS. 27 A-27C illustrate deployment of a fastener of the presentinvention, wherein FIG. 27 A shows the fastener penetrating the tissuesurface; FIG. 27B shows fastener self-reconfiguration during deployment;and FIG. 27C shows the fastener fully deployed in tissue.

FIGS. 28A and 28B illustrate two different fastener placements forsecuring a tissue fold to produce a plication according to the presentinvention, wherein FIG. 28A shows the fastener penetrating completelythrough the tissue; and FIG. 28B shows the fastener not penetratingcompletely through the tissue.

FIGS. 29A and 29B illustrate alternative embodiments for fastenerapplicators according to the present invention, wherein FIG. 29A showsthe fastener being deployed directly from a central channel; and FIG.29B shows the fastener being deployed with the aid of insertion guides.

FIGS. 30A and 30B illustrate one embodiment of an integrated all-in-onedevice for approximating and fastening tissue, wherein FIG. 30A shows anoverview; and FIG. 30B shows a close up of the distal end.

FIGS. 31A-31C illustrate use of a device according to one embodiment ofthe present invention for performing the surgical procedure of thepresent invention, wherein FIG. 31A shows formation of an invaginatedtissue fold; FIG. 31B shows deployment of a fastener into theapproximated shoulders of the invaginated tissue fold; and FIG. 31Cshows the fastener securing the tissue fold to produce a plication.

FIGS. 32A-32C illustrate use of a device according to another embodimentof the present invention for performing the surgical procedure of thepresent invention, wherein FIG. 32A shows formation of an invaginatedtissue fold; FIG. 32B shows deployment of a fastener into theapproximated shoulders of the invaginated tissue fold with the aid ofinsertion guides; and FIG. 32C shows the fastener securing the tissuefold to produce a plication.

FIGS. 33A and 33B illustrate an embodiment of a fastener of the presentinvention, wherein FIG. 33A shows the deployed configuration; and FIG.33B shows the predeployed configuration.

FIGS. 34A-34C illustrate deployment of a fastener of the presentinvention, wherein FIG. 34A shows the fastener penetrating the tissuesurface; FIG. 34B shows fastener self-reconfiguration during deployment;and FIG. 34C shows the fastener fully deployed in tissue.

FIGS. 35A-35C illustrate use of a device according to one embodiment ofthe present invention for performing the surgical procedure of thepresent invention, wherein FIG. 35A shows formation of an invaginatedtissue fold; FIG. 35B shows deployment of a fastener into theapproximated shoulders of the invaginated tissue fold; and FIG. 35Cshows the fastener securing the tissue fold to produce a plication.

DETAILED DESCRIPTION OF THE INVENTION

Methods of the present invention provide effective reduction of thefunctional volume of the gastrointestinal tract (e.g., stomach) using anextragastric gastroplasty procedure. In this procedure, a portion of thegastrointestinal tract is reconfigured by invaginating and approximatingtissue to form one or more tissue folds, and then securing the one ormore tissue folds in order to produce one or more plications. While thefollowing detailed descriptions refer in general to reducing thefunctional volume of the gastrointestinal tract, the stomach inparticular, it should be recognized that the invaginaton, approximationand securing methods of the present invention may be used on other bodytissues and for other interventional purposes, within the scope of thepresent invention.

Gastric reduction procedures of the present invention generally accessthe gastrointestinal tract via the abdominal cavity. This is mosttypically accomplished using conventional laparoscopic techniqueswherein the patient is anesthestetized, one or more small incisions aremade through the abdominal wall, and a pneumoperitoneum is establishedby insufflation, thereby allowing the insertion of imaging devices andone or more interventional instruments through laparoscopic ports, alsoknown as trocars. Alternatively, methods of the present invention mayalso be carried out when access to the abdominal cavity andgastrointestinal tract is obtained using even less invasive,non-laparoscopic techniques. A variety of such non-laparoscopictechniques may be utilized within the scope of the present invention,typically involving grasping and lifting, or otherwise retracting theabdominal wall to create sufficient working space within the abdominalcavity, without the need for insufflation. Alternatively, the methodsand devices of the present invention may also be adapted for flexibleendoscopic use, allowing access to the abdominal cavity and externalsurface of the gastrointestinal tract to be obtained by first enteringthe body through a natural orifice (e.g. esophagus, anus or vagina),then penetrating through the wall of an anatomical lumen into theabdominal cavity.

Once abdominal access has been obtained, the medical professionalemploys one or more cameras or other imaging devices, along with avariety of tools known in the art, to manipulate the internal organsand/or tissues to expose the region of the gastrointestinal tract ofinterest. In preferred embodiments of the present invention, at leastthe anterior portion of the stomach is exposed sufficiently to allow forits reconfiguration. This may require dissection and/or removal of atleast a portion of the omentum, and it may require lifting and/orpartial retraction of the liver, both of which are relatively simpleinterventional steps that are well known in the art. The subsequentreconfiguration and gastric reduction may then be performed, preferablyusing the devices and systems of the present invention, which aredescribed in detail below.

FIG. 1 schematically illustrates the relevant portion of thegastrointestinal tract (anterior view), both pre-procedure (FIG. 1A) andpost-procedure (FIG. 1B). To aid in the following discussion, it ishelpful to first distinguish the various anatomical structures in FIG.1A. The stomach itself lies between the esophagus 105 and pylorus 110.The anterior wall 115 of the stomach is shown, along with the fundus120, the greater curvature 125, and lesser curvature 130. Twocross-sectional views of the stomach are shown in FIG. 1A1 at X-X and inFIG. 1A2 at Y-Y. It is helpful to point out the major tissue layers ofthe stomach wall, as illustrated in FIG. 1A3. Starting intragastricallyand moving outward, the innermost tissue layer is the mucosal tissuelayer 150, then there is a submucosal connective tissue layer 152, themuscularis tissue layer 155, and the exterior serosal tissue layer 160that covers the extragastric surface of the stomach.

FIG. 1B illustrates a stomach following gastric reduction according tomethods of the present invention. As shown in FIGS. 1B1 and 1B2, thestomach now exhibits a significantly reduced cross sectional area (e.g.at X-X and Y-Y) and the functional volume of the stomach has beendecreased approximately 50% as a result of single fold 180 being placedin the anterior wall 115 of the stomach. As shown, fold 180 is locatedapproximately midway between the greater curvature 125 and lessercurvature 130, and extends approximately longitudinally from near fundus120 to near pylorus 110. As can be seen in sections X-X and Y-Y of FIGS.1B1 and 1B2, fold 180 was created by invaginating and approximating thetissue of the anterior wall 115 of the stomach so as to bring theserosal tissue layer 160 into contact with itself. Fasteners are thenapplied to the tissue brought together to produce the plication in thewall of the stomach.

In a preferred embodiment of the present invention, a single fold andplication is produced in the above described manner and location, asillustrated in FIG. 1B; however, in other embodiments, two or more suchplications may be produced. Although the plication is illustrated asbeing formed approximately midway between the greater and lessercurvatures of the stomach, it will be appreciated that other areas ofthe stomach or gastrointestinal wall may be used, as may be necessarybased on individual anatomy and the surgeon's desire to achieve thetargeted functional gastric reduction, while minimizing the overallinvasiveness of the procedure. According to the present invention thefunctional volume of the stomach is preferably decreased at least 20%,is more preferably decreased at least 30%, and is most preferablydecreased at least 40%. In morbidly obese patients, a functional volumereduction of 50% or more may be achieved in order to promote the desiredexcessive weight loss. In one live animal surgery where the devicesdescribed below have been tested in a clinical setting, it hasunexpectedly been found that volume reductions exceeding 80% arepossible by exposing and plicating along substantially the full lengthof the greater curvature of the stomach.

In FIG. 1B, securing means comprising a row of individual staples 185are placed substantially along the length of fold 180. As shown in FIG.1B2 at section Y-Y, staples 185 grasp tissue shoulders 195 that areformed where the opposing tissue layers of the tissue fold intersect thecircumference of the stomach. As can also be seen in section Y-Y,according to a preferred embodiment of the present invention, staples185 engage tissue shoulders 195 by penetrating only through serosaltissue layer 160 and underlying muscularis tissue layer 155, withoutpenetrating completely through the stomach wall to breach or otherwisecompromise mucosal tissue layer 150. As can also be seen in section Y-Y,according to another preferred embodiment of the present invention, theapproximated tissue surfaces within the tissue fold are configured suchthat there is substantially intimate serosal-to-serosa contact withinthe plication 190.

FIG. 2 illustrates in greater detail the intermediate steps of theprocedure, according to one embodiment of the present invention. FIG. 2Aand FIG. 2E are identical to FIG. 1A and FIG. 1B, respectively, and arerepeated for completeness. FIG. 2B, FIG. 2C and FIG. 2D are helpful toexplain other aspects of the intermediate steps. In FIG. 2B, forexample, prior to commencing with the reconfiguration portion of theprocedure, the region of interest on anterior wall 115 may be visuallyidentified, marked or mapped out to aid subsequent steps of theprocedure. For example, it may be desirable to identify and/or indicatethe target position and length of the fold centerline 202, as well asthe bounding lines 204 and 206 where the tissue will be contacted,engaged and/or secured. The location of bounding lines 204 and 206define the depth of the tissue fold to be created, as well as thesurface area of tissue that will be approximated during creation of thetissue fold. Identification, marking and/or mapping of the tissuestructures and/or locations can be carried out according to methods wellknown in the art, for example, inks, dyes, adhesives, implantable tags,clips, fasteners, radio-opaque markers, fluorescent markers, cauterizingmarks, and the like, may be used.

FIG. 2C schematically illustrates the early steps in the procedure,starting at one end of the target area (e.g. near the pylorus) andworking progressively in one direction (e.g. toward the fundus). Itshould be recognized, however, that this progression is optional, andthat it is just as feasible to start near the fundus and work toward thepylorus, to start anywhere along the length of the intended fold andwork in both directions, or any combination of the foregoing. To form atissue fold, the tissue is contacted and/or engaged at two or morelocations, and various combinations of relative motions are then used toensure the tissue is invaginated as the opposing tissue surfaces areapproximated. Examples of such combinations of relative motions includeone or more motions selected from the group consisting of pushingmotions, pulling motions, twisting motions, and shearing motions.

In FIG. 2C, for example, tissue is contacted and engaged at locations208 and 210 on opposite sides of a fold centerline location 212.Relative motion between central location 212 and the tissue contact andengagement locations 208 and 210, is represented in FIG. 2C1 by pushingforce vector 214 and pulling force vectors 216 and 218, respectively.These motions invaginate the tissue and approximate the opposing tissuesurfaces, while bringing tissue shoulders 195 toward each other forsubsequent securing. The relative motion illustrated may be achieved,for example, by holding central location 212 substantially stationaryand pulling the tissue engagement points 208 and 210, or by holding thetissue engagement points 208 and 210 substantially stationary andpushing on the central location 212, or alternatively, any combinationof pushing and pulling may be used to achieve the same effect.

After the tissue has been approximated to create the tissue fold 180 asdescribed above, and tissue shoulders 195 have been brought togetherinto proximity of one another, a tissue fastener 185 is then applied atthat location to secure the plication 190, as shown in FIG. 2D. In FIG.2D, exemplary tissue fastener 185 is schematically shown as a box-typeof interventional staple, similar in form and function to a box-typestaple known in the art of interventional skin stapling for use in woundclosure applications. However, it should be obvious to those skilled inthe art that, within the scope of the present invention, a wide varietyof mechanical elements may be used as tissue fasteners 185 for thepurpose of anchoring, fastening, holding, attaching, or otherwisesecuring tissue surfaces 180 to produce plication 190. Examples ofsuitable tissue fasteners that may be used include but are not limitedto sutures, staples, screws, tacks (e.g. U-shaped, circular and helicalfasteners), clips, hooks, clamps, t-tags, and the like. In a preferredembodiment of the present invention, tissue fasteners 185 are preferablyapplied at least directly across tissue shoulders 195 at more than onelocation along the length of tissue fold 180, more preferably at severalrelatively closely spaced locations to secure the plication.

The tissue engagement, approximation and fastening steps are repeatedany number of times as is necessary to completely form and secure theone or more tissue plications. In the example provided herein, the finalresult is shown schematically in FIG. 2E.

For convenience, the procedure may progress sequentially in onedirection along the length of the intended fold, as illustrated in FIG.2D, effectively producing the plication in a manner similar to closing azipper. However, sequential advancement is not required, and the surgeonmay use discretion in deciding where to begin and how to advance theprocedure.

At each of one or more locations along the length of the intended fold,the tissue is invaginated, approximated and secured with one or moretissue fasteners before moving to the next location. In one embodiment,a device may be provided that allows simultaneous or sequentialplacement of multiple tissue fasteners while the invaginating andapproximating tool is placed and held at one location. Alternatively, inanother embodiment, a device may be provided that allows placement of asingle tissue fastener along a substantial length, or even along thecomplete length, of the tissue fold, while the invaginating andapproximating tool is held at one location.

According to one embodiment of the present invention, prior to securingthe approximated tissue to produce the one or more plications, at leasta portion of the surface area of the serosal tissue enfolded by the oneor more plications is selectively treated to promote serosal-to-serosaltissue bonding. There is a considerable body of clinical knowledgeregarding the mechanisms of abdominal adhesion formation, and a varietyof methods known to those skilled in the art may be used to selectivelytreat the serosal tissue surfaces to promote tissue adhesion of theserosal tissue layers adjoining one another inside the tissue foldforming the plication. Examples of such tissue treatments include butare not limited to mechanical disruption methods (e.g. abrasion), energydeposition methods (e.g. RF, ultrasonic, electromagnetic, and the like),methods involving treatment using liquids (e.g. chemicals,pharmaceuticals, adhesives, etc.) and methods involving treatment usingsolids (e.g. powders, films, etc.). Regardless of the tissue treatmentmethod used, an important aspect of this embodiment is that serosaltissue bonding or adhesion is promoted over a sufficiently largeinterfacial surface area across the approximated tissue boundary withinthe plication to achieve a strong and durable serosa-to-serosa bondpost-operatively.

In yet another embodiment of the present invention, additional tissuefasteners may also be optionally applied while the tissues are beingapproximated to aid in forming, stabilizing and/or providing additionalstrength to the resulting tissue plication, as well as to furtherpromote the formation of a strong serosa-to-serosa bond inside theplication. For example, as illustrated in the enlarged cross sectionalview X-X shown in FIG. 3B, in addition to outer tissue fastener 305(similar to the tissue fastener 185 described previously), one or moreadditional internal tissue fastener 310 may be applied across thecontact area of the approximated tissue surfaces within the fold whileit is being formed, such that after the plication is completed, the oneor more additional internal tissue fasteners 310 are located inside theplication for the purpose of better securing the tissue across theapproximated tissue surfaces. Additional internal tissue fastener 310may be identical to outer tissue fastener 305, being placed by the samedevice, or in an alternative embodiment, additional internal tissuefastener 310 may have a different design and/or be placed usingadditional devices. Note that additional internal tissue fastener 310also preferably penetrates only the serosal and muscularis tissuelayers. Although FIG. 3 illustrates the use of a box-type staple, as inthe case of tissue fastener 185 described previously, this embodiment ismerely illustrative and a wide variety of alternative fasteners existthat may be used for the outer tissue fastener 305 and additionalinternal tissue fastener 310, within the scope of the present invention.

In yet another embodiment of the present invention, more than one tissueplication may be produced according to the previously described methods.For a variety of reasons, it may be advantageous in some cases toproduce two or more plications. These advantages may include, forexample, allowing a greater range of effective volume reductions in thestomach to be achieved, allowing smaller laparoscopic devices to beused, allowing the surgeon more flexibility in positioning of theplications relative to the stomach or surrounding organs, for reducingthe maximum forces generated on the individual securing means, and soon. FIGS. 4A and 4B schematically show an example according to oneembodiment of the present invention in which tissue two adjacent tissuefolds 402 and 404 have been placed in the anterior wall of the stomach,running more or less parallel to one another. As can be seen in FIG. 4Bin the enlarged view of cross section X-X, tissue fold 402 has beensecured with tissue fastener 405 to produce a first plication 410,whereas tissue fold 404 has been secured with tissue fastener 415 toproduce a second plication 420. It should be obvious to those skilled inthe art that within the scope of the present invention, it is possibleto produce any number of individual and separate plications in themanner described previously, each of which plication may becharacterized individually in terms of length, depth, position, numberand type of fasteners placed, and so on, to achieve the intendedinterventional result.

Interventional Devices and Systems

Interventional devices for performing methods of the present inventionare described herein that, taken together, comprise systems of thepresent invention. The devices and systems of the present inventionprovide the ability to carry out the above described volume reductionprocedures in a safe, efficient and minimally invasive manner, which isdifficult or impossible to accomplish using prior art devices. It willbe appreciated that while the devices and systems of the presentinvention are described below with respect to their use in gastricreduction methods of the present invention, they have utility and may beused for general approximation and fastening of other types of soft bodytissues and in other types of interventional procedures as well.

In general, at least one handheld interventional instrument is providedhaving one or more integrated tool assembly(ies) adapted for placementat an interventional site, such as within the abdominal cavity, incombination with one or more actuator(s) positioned remotely from thetool assembly and providing operator control of the tool assembly(ies)during an intervention. The tool assembly is preferably capable ofengaging tissue at two or more separate locations, and then invaginatingand approximating tissue to effectively create a tissue fold between thetissue engagement locations. In one embodiment, the tool assemblycomprises at least two tissue engagement mechanisms (e.g. clamps,grippers, forceps, jaws, hooks, barbs, vacuum ports or the like, orcombinations of these mechanisms) positioned at or in proximity to thedistal end of an elongate shaft of a laparoscopic device. The tissueengagement mechanisms may be positionable by means of a remote actuator,or they may be mounted on supporting members that may be positionable toengage desired tissue sites. Using this device, the laparoscopic shaftis positioned within the abdominal cavity, and the distal end of theshaft is positioned at a first desired tissue engagement site, where atissue engagement mechanism is engaged with the tissue. The operatorthen repositions the shaft by moving it to a second location, draggingthe first engaged tissue location toward the second, and therebyapproximating the first and second tissue locations. The approximatedtissues may then be fastened to one another to secure the plicationusing fasteners applied with an independent device or an integratedassembly of the tissue approximation device.

In another embodiment, a first tissue engagement mechanism may bepositioned at the distal end of the elongate shaft of a laparoscopicdevice, while a second tissue engagement mechanism may be positioned atthe distal end of an extendible member that can be manipulated by anoperator to move away from the axis of the device shaft to position thesecond tissue engagement mechanism at a second location, remote from thedistal end of the device. The extendible member may be substantiallyrigid, or it may be flexible, or it may have both substantially rigidand flexible portions, and it may either be deployable from inside theelongate shaft of the laparoscopic device, or attached near the distalend of the shaft by mechanical means. In one embodiment, a proximal endof an extendible member is attached near the distal end of the elongateshaft using a pivot connection, a hinge connection, a flexibleconnection, or the like, that allows the extendible member to beoperatively and selectively actuated to move its distal, operating end(comprising a tissue engagement member) away from the axis of thelaparoscopic device to engage tissue. In operation, the distal end ofthe shaft of the laparoscopic device is first positioned at a desiredtissue surface and the tissue is engaged at a first site. The extendiblemember and its associated tissue engagement mechanism is then deployed,extending away from the axis of the shaft to independently engage tissueat a second location. The extendible arm and its associated tissueengagement mechanism is then retracted, under control of the operator,and the second engaged tissue location is drawn in toward the axis ofthe shaft and thereby approximated adjacent the first engaged tissuesite. An invaginated tissue fold projecting away from the distal end ofthe device and into the gastrointestinal space is created as the twotissue sites are drawn together and approximated.

In other embodiments, described in detail below, two or more suchextendible members are provided on an interventional device, eachextendible member having at least one tissue engagement mechanism,generally (but not necessarily) positioned at its distal end, such thatthe engagement of tissue at multiple separate locations can beaccomplished without requiring the shaft of the laparoscopic deviceitself to contact the tissue surface. The extendible members may beactuated and positioned separately and independently of one another, orthey may be actuated and positioned simultaneously and in coordinationwith one another. Operation of this type of device involves deployingeach of the extendible members and their associated tissue engagementmechanisms, independently or in coordination, to contact the tissueengagement mechanisms at two locations on the tissue, then approximatingthe engaged tissue to form an invaginated tissue fold by moving at leastone of the extendible members toward the other and, in some embodiments,by moving multiple extendible members toward a central location, therebyapproximating the engaged tissue substantially near the distal end ofthe device (or along a longitudinal axis extending therefrom).

Another embodiment that provides an alternative to using two or moreextendible members to engage tissue involves the use of tethers. In thiscase, the distal end of the shaft of a laparoscopic instrument may bepositioned to sequentially engage tissue at each of two or morelocations using releasable tissue engagement mechanisms mounted onretrievable tethers, wherein each tissue engagement mechanism, afterbeing engaged in tissue, is released from the end of the shaft of thelaparoscopic instrument, yet remains connected to the instrument by atether (e.g. a suture, wire, or the like). This allows the instrument tobe moved freely between each desired tissue engagement location todeploy two or more tissue engagement mechanisms at different tissuesites. Subsequently, the tethers may be selectively retrieved, orretracted back toward the shaft of the device to draw the engaged tissuesites toward one another, thereby approximating the tissue sites.Alternatively a cinching member through which the flexible tethers passmay be slid distally down the length of tethers, causing the engagedtissue locations to move toward each other, thereby approximatingtissue. Retrieval of the tether(s) and/or operation of the cinchingmember(s) is under the control of an operator using associated actuationmechanisms.

It will be appreciated that methods and systems of the present inventionmay be used in connection with other diagnostic and therapeutic methodsand devices. Methods of the present invention may thus be used, forexample, in connection with conventional diagnostic and therapeuticmethods and may involve the administration of diagnostic or therapeuticagents, agents for visualizing the interventional site, and the like.Similarly, device components of the present invention may be used inconnection with various procedures and agents that are known in the art.Certain device components that are intended for introduction to theinterventional site, such as tissue engagement mechanisms, probes,extendible members, fasteners, and the like may be administered inassociation with various types of diagnostic or therapeutic agents, ormay be coated or impregnated with such materials. Suitable agents mayinclude clotting agents, healing agents, hydrophobic and/or hydrophilicmaterials, agents promoting lubricity, and the like.

FIGS. 5A-5F illustrate an exemplary tissue approximation deviceaccording to one embodiment of the present invention. An overview ofdevice 500 is shown in FIG. 5A in the pre-deployed configuration, andFIG. 5B shows a distal end of device 500 in the deployed configuration.Device 500 comprises an elongate tubular member 502 having at least oneinternal working channel 504, handle assembly 506 positioned at theproximal end, and approximating tool assembly 508 positioned at thedistal end, wherein approximating tool assembly 508 is shown in thecollapsed (i.e. pre-deployment or fully retracted) state, substantiallyconfined within working channel 504. In the case of minimally invasivelaparoscopic surgery, this low profile collapsed state configuration isuseful for delivery of the instrument to and removal of the instrumentfrom an internal site in the patient, such as the abdominal cavity,through a standard trocar. It is therefore generally desirable that theouter diameter of elongate tubular member 502 be as small as possible,preferably 15 mm or less, more preferably 12 mm or less and, in someembodiments, 5 mm or less. Also shown in FIG. 5A, actuating mechanismssuch as a trigger 510, slider 512, and plunger 514 are provided inconnection with handle assembly 506. Also shown is rotating collar 516that allows the orientation of handle assembly 506 to be independentlyadjusted by the operator relative to the orientation of approximatingtool assembly 508.

FIG. 5B shows an enlarged cross section view of the distal end of device500, with approximating tool assembly 508 being shown in the collapsedstate. In this configuration, located along longitudinal axis 518 ofworking channel 504 are two (or more) extendible members 520, andpushing member 522, each being operatively connected to an actuatingmechanism operated at the handle assembly 506, as described below. Eachof said extendible members 520 is configured at its distal end with atissue engagement mechanism 524 comprising one or more mechanisms forcontrollably and selectively grasping, grabbing, gripping, piercing,holding or otherwise engaging tissue. In the example shown, tissueengagement mechanism 524 incorporates a tissue hook 526. Hook 526 has agenerally pointed distal end for penetration of tissue and has arelatively short curved segment, thus limiting the degree of tissuepenetration. Tissue engagement mechanisms having a generally pointed andsharp tissue penetration structure for penetrating tissue, such as therelatively tough serosal layer forming the exterior gastric wall, arepreferred in many embodiments.

FIG. 5C shows an enlarged view of the distal end of tissue approximationdevice 500, with approximating tool assembly 508 being shown in theextended state, i.e. after being deployed by the operator. In thisembodiment, extendible members 520 open, or extend, along a predefinedpath as they're released from the distal end of the shaft. An actuatingmechanism such as plunger 514 is operatively connected to extendiblemembers 520, such that when plunger 514 is axially displaced into handleassembly 506, extendible members 520 move distally along longitudinalaxis 518 and thereby extend outward from working channel 504 beyond theend of elongate tubular member 502. After deployment to an expandedstate, each of extendible members 520 is positioned with its distal ends524 spaced apart from and positioned on opposite sides of longitudinalaxis 518 from an opposing extendible member.

The degree of extension of the extendible members, and the spacing 521between distal ends 524 of extendible members 520 may be governed by thedegree of deployment out of shaft 502. In some embodiments, both thedegree of extension of distal ends 524 from the shaft 504, indicated aslongitudinal spacing 519, and the distance between extended distal ends524 are selectably controllable by the operator to facilitate tissueengagement at desired locations, and to facilitate the creation of atissue plication of the desired dimensions, thereby producing thedesired gastric volume reduction.

Tissue approximating device 500 illustrated in FIGS. 5A-5F additionallycomprises a pushing member 522 operatively connected to an actuator,such as slider 512, such that when slider 512 is translated away fromits proximal (fully refracted) position, the distal end of pushingmember 522 moves along longitudinal axis 518, thereby extending out ofworking channel 504 a distance 505 beyond the end of elongate tubularmember 502. The extension of pushing member 522 facilitates invaginationof a tissue fold and formation of a tissue plication as two or moretissue sites are approximated. Pushing member 522 may be operatedindependently of, or in coordination with, extendible members 520. Inone embodiment, pushing member 522 is extended out of working channel504 as the extendible members 520 are extended and the tissue engagementmechanisms are positioned to engage tissue.

Illustrative operation of a tissue approximation device 500 illustratedin FIGS. 5A-5F is described below. Following insertion of the shaft intothe intra-abdominal space and positioning of the distal end of the shaftnear a desired tissue approximation site, extendible members 520 aredeployed from a collapsed state to an expanded state to prepare thedevice for subsequent tissue engagement steps. In one embodiment,extendible members 520 are expanded by an actuator that pushes themembers out of, or releases them from the shaft, as follows. In thiscase, extendible members 520 are produced from a highly flexible andelastically deformable material (e.g. flexible polymers, flexiblemetals, shape change materials and combinations thereof may be used) andare made in a shape when in the expanded state having an outward (i.e.away from longitudinal axis 518) curvature. As the extendible members520 are released from the working channel 504, they assume theirexpanded state, and the distal tissue engagement mechanisms are broughtinto contact with the tissue surface. Due to their flexible nature andoutwardly curved shape, extendible members 520 flex elastically andcontinue to assume a progressively more extended condition as theoperator continues releasing them from the shaft, causing distal armportions 524 to slide outward along the tissue surface, becoming spacedapart, until the distal tissue engagement mechanisms are located in thedesired positions for tissue engagement, as described below.

In another embodiment, extendible members 520 are designed to bereleased from the collapsed state to the expanded state in aself-actuating manner, automatically achieving the desired tissueengagement configuration when extended out of working channel 504 beyondthe end of elongate tubular member 502. Such self-actuating motions canbe achieved by various methods known in the art. For example, in onepreferred embodiment of the present invention, extendible members 520are produced from a highly elastic material (e.g. spring steel, hardenedstainless steel, a shape change material such as a superelastic NiTialloy, superelastic polymer, or the like) and are formed duringmanufacturing into the desired final deployed shape by mechanical and/orthermomechanical processing means known in the art. Extendible members520 are then biased (i.e. mechanical potential energy is stored, similarto a pre-loaded spring) by elastically deforming and loading them intoworking channel 504 to thereby provide the device in its collapsedstate. As extendible members 520 are then pushed out of working channel504 during deployment, the stored energy is released and extendiblemembers 520 automatically return to the pre-determined shape desired forsubsequent tissue engagement when brought into contact with the tissuesurface. It will be appreciated that different assemblies of extendiblemembers having different dimensions, different curvatures, differentelastic properties, and the like may be provided for use in a tissueapproximating device of the present invention and an operator may selectan appropriate extendible member assembly having the desired dimensionsand extension properties and install the desired assembly in the workingchannel prior to an intervention.

In yet other embodiments, deployment of extendible members 520 from thecollapsed state to the expanded state may be accomplished, by means ofan actuating mechanism, by any combination of manual pushing to causeexpansion and self-actuating expansion mechanisms. Factors that may beadjusted to optimize the above described reconfiguration and deploymentmotions include, for example, the cross sectional shape, curvatures,mechanical properties, length, etc. of extendible members 520. It shouldalso be obvious to those skilled in the art that, within the scope ofthe present invention, other mechanical actuation mechanisms ofproviding the desired reconfiguration and deployment to adjust theextendible members from the collapsed state to the expanded state mayalso be used. Such actuating mechanisms may comprise, for example,springs, levers, cams, gears, linkages, and the like may be used.

Distal ends 524 of extendible members 520 each incorporate one or moretissue engagement means configured to allow targeted tissue surface 535to be selectively and controllably engaged by the device when actuatedby the operator. Various tissue engagement mechanisms are known in theart may be employed to provide secure and robust tissue engagementhaving sufficient strength, for example, to allow the tissue to besubsequently pulled or otherwise manipulated without disengaging,slipping or tearing. Tissue engagement mechanisms that may be usedinclude, for example, hooks, barbs, grippers, teeth, clamps, jaws,clips, t-tags, and the like. According to one embodiment of the presentinvention, as shown in FIG. 5C, tissue hooks 526 are located at thedistal ends 524, and further comprise sharpened points 528 to promotetissue penetration. While extendible members 520 are in the expandedstate, distal ends 524 and tissue hooks 526 are positioned such thatsharpened points 528 curve slightly downward (distally) and inward(toward longitudinal axis 518). As a result, when pushed slightlydownward onto the surface of the tissue, elastic deformation ofextendible members 520 causes distal ends 524 to first move slightlyoutward. Then, when extendible members 520 are either lifted slightly(e.g. by the surgeon lifting device 500) or alternatively, whenretraction of the extendible members is initiated by the operator (asdescribed below), tissue hooks 526 move slightly downward and inward,thereby causing sharpened points 528 to pierce, penetrate and securelyengage the tissue at tissue engagement locations 530, as shown in FIG.5D. Preferably, distal ends 524, tissue hooks 526 and sharpened points528 are designed such that secure tissue engagement is achieved bypenetrating only the serosal tissue surface 535 (i.e. the serosal tissuelayer), or a combination of the serosal and muscularis tissue layers,without penetrating the mucosal tissue surface 540.

While more complicated mechanical tissue engagement means may beemployed in accordance with the present invention (e.g. hinged jaws,mechanical clamps, forceps, grippers, vacuum actuated mechanisms, andthe like) there are several advantages to the embodiment describedabove, and similarly designed self-actuating embodiments. One advantage,for example, is that it is a simple, single component design having lowproduction cost. Additionally, successful operation of this device isnot particularly dependent upon operator technique (i.e. nosophisticated hand motions or unusual device manipulations arerequired), successful operation instead being more dependent upon devicedesign factors that control, for example, the directions and magnitudesof the forces generated by extendible members 520 during the pushing andpulling motions involved in deployment and/or retraction of the device.Examples of design factors that may be optimized in the self-actuatingdesign embodiments of the present invention include the shape, physicaldimensions, geometrical angles, surface finish, and the like, ofextendible members 520, distal ends 524, tissue hooks 526, and sharpenedpoints 528, as well as their materials of manufacture and mechanicalproperties.

In one embodiment, extendible members 520 have a non-circular, generallyflattened cross section to effectively increase the lateral (i.e. out ofplane) stiffness when extendible members 520 are extended. Examples ofsuitable non-circular cross sectional shapes include square crosssections, rectangular cross sections, triangular cross sections, arcuatecross sections, hemispherical cross sections, oblong or flattenedcross-sections, and combinations of the foregoing. The cross sectionalshape, physical dimensions, mechanical properties, and so on, ofextendible members 520 may be designed having variations along theirlength to provide improved deployment, tissue engagement or retractioncharacteristics.

In another embodiment, extendible members 520 have a pre-determinedshape when in the expanded state that includes at least two bends havingradii of curvature in substantially opposing directions. Such a shape,as illustrated in FIGS. 5C-5E and explained above, may be utilized toinitially give rise to a slight downward motion of distal ends 524, inaddition to the inward motion that occurs during the retraction ofextendible members 520 back into working channel 504, wherein thecombined initial downward and inward motions of distal ends 524effectively promotes tissue penetration and secure tissue engagement ofsharpened points 528 on tissue hooks 526 upon actuated retraction ofextendible members 520. The combined initial downward and inward motionsof distal ends 524 that promote tissue penetration and secure tissueengagement may also be achieved using other designs obvious to thoseskilled in the art. This embodiment simplifies the operation, improvesconsistency, reduces procedural times and risk of complications, byminimizing reliance on individual operator technique and instead takingadvantage of highly controlled and repeatable device motions.

After tissue has been securely engaged by approximating tool assembly508, as described above, the operator actuates device 500 to initiatethe tissue invagination and approximation step, wherein the desiredtissue fold is formed by bringing serosal tissue surfaces between theengaged tissue sites in contact with each other, so that the mucosaltissue surface 540 forms a plication extending into the gastrointestinallumen. FIG. 5E illustrates this process. In the example provided, theoperator selectively activates device 500 remotely using trigger 510provided within handle assembly 506, which is operatively connected toextendible members 520 in a manner such that, as trigger 510 issqueezed, extendible members 520 are thereby controllably retracted andpulled back into working channel 504, as indicated by retraction forces531. The mechanisms used to operatively connect trigger 510 toextendible members 520 may include various mechanical elements known tothose skilled in the art, such as gears, transmissions, levers, pivots,linkages, and the like, whether manual or automated, in order to providethe retraction forces at the working (distal) end of the device, whilekeeping the actuating mechanisms operated by the operator at aconvenient level.

The retraction of extendible members 520 causes tissue engagementlocations 530 to be gradually pulled inward toward longitudinal axis518. In one device embodiment that incorporates a pushing member, theoperator may selectively and independently actuate pushing member 522from within handle assembly 506 (i.e. using slider 512) as the tissueengagement locations are drawn toward one another. The pushing member isextended distally along longitudinal axis 518 to contact and pushagainst the tissue, e.g. with pushing force 532, at a location betweentissue engagement points 530. This promotes tissue invagination in thedesired manner while the engaged tissue is approximated, as shown inFIG. 5E. Once extendible members 520 have been fully retracted bycomplete actuation of trigger 510, the tissue engagement locations 530have been brought into approximation near the distal end of elongatetubular member 502 to create tissue fold 540 as shown in FIG. 5F. Inthis illustration, pushing member 522 is shown remaining in the fullyextended position.

The combination of extendible members and a pushing member in devices ofthe present invention, enabling the combined action of pulling tissueengagement points 530 toward one another via retraction of extendiblemembers 520 while simultaneously having the user selectable option topush against the tissue between tissue engagement points 530 withpushing member 522 promotes creation of a uniform and consistent tissuefold, as shown in FIG. 5F. In preferred embodiments of the presentinvention therefore, operation of the device in the described mannereffectively approximates opposing serosal tissue surfaces 535 inside thetissue fold, providing substantially intimate serosa-to-serosa contact,without forming wrinkles, bunches, gaps, or the like, and withoutpenetrating the mucosal tissue surface 540.

In other embodiments of the present invention, additional userselectable controls may be optionally provided within handle assembly506. For example, controls may be optionally provided to allow thesurgeon to adjust the span 521 of extendible members 520 when in theexpanded state, and the distal extension distance 505 and pushing force532 of pushing member 522. Independent, operator controlled actuationmechanisms may be provided for each of the more than one extendiblemember 520, and the actuation mechanisms may control the speed and forcethat may be used to retract extendible members 520, as well as otheroperating parameters. It should also be recognized that the actuationmeans described above are exemplary, and that other actuation andcontrol mechanisms that are known to those skilled in the art may beused and are considered within the scope of the present invention. Forexample, actuation may be accomplished manually by one or more variousmeans known in the art (e.g. triggers, levers, buttons, knobs, or thelike) or by one or more various powered means known in the art (e.g. ACor DC electric motors, compressed gas, vacuum, or the like), or by anycombination of the foregoing.

As described previously, according to one embodiment of the presentinvention, it is desirable to selectively and therapeutically treat theserosal tissue layer to promote bonding or adhesion of the serosallayers that abut one another within the plication. This may beaccomplished using device 500 in various ways. For example, in oneembodiment illustrated in Figures SC-SF, the distal tip and/or lateralsurfaces of pushing member 522 may be used to mechanically disturb anddisrupt the thin layer of mesothelial cells that form the outermostcovering of the serosa. Since the layer of mesothelial cells coveringthe serosa is quite thin and fragile, it is easily disrupted, andpushing member 522 may be scraped, dragged or otherwise frictionallymoved across the surface of the tissue to produce the desireddisruption. To further aid in disrupting the serosal tissue surface andpromote tissue adhesion, pushing member 522 may be modified, forexample, by incorporating roughening features 523, illustrated asprotuberances in Figures SC-SF. As will be obvious to those skilled inthe art, a wide variety of such roughening features and arrangements maybe used to accomplish the desired serosal treatment, for example,ridges, bumps, bristles, teeth, scales, serrations, and the like may beused.

The optional serosal treatment described above may be carried out beforethe tissue fold is formed, after the tissue fold is formed but prior tothe securing means is applied, after the tissue fold is formed and thesecuring means is applied, or any combination of the foregoing. Forexample, prior to actuating extendible members 520 to engage tissue, thedistal end of pushing member 522 may be moved across substantially theidentified area of serosal tissue to be included within the tissue foldin a sweeping or painting type of motion. Alternatively, the lateralsurfaces of pushing member 522 contact and slide across the opposingserosal tissue surfaces of the tissue fold when pushing member 522 isretracted from within the tissue fold (as is evident in FIG. 5F),thereby disrupting at least a substantial portion of the serosal tissuesurface during normal device operation. In this case, rougheningfeatures 523 present on the lateral surfaces of pushing member 522 mayensure more uniform and consistent serosal treatment, leading to a moreeffective and stronger serosa-to-serosa tissue bond.

In another serosal treatment embodiment, ports may be provided near thedistal tip of shaft 502 and/or along pushing member 522 such that, whenthe shaft and/or pushing member lumen is connected to a supply of sourcematerial (e.g., a liquid reservoir located within or attached to theproximal handle assembly 506), the device provides controlled dispensingof a chemical or therapeutic agent (e.g. liquid, gas, solid powder,solid film, or combinations thereof) onto the tissue surface thatpromotes tissue bonding and adhesion. Alternatively, the distal tip ofshaft 502 and/or pushing member 522 may optionally incorporate an energydeposition mechanism capable of delivering energy to the target tissue.Exemplary energy deposition mechanisms include, for example, componentscapable of RF cauterizing, electro-cauterizing, ultrasonic vibration,and the like.

According to the present invention, once the tissue has beenapproximated and the desired tissue fold has been created as describedabove, fasteners are then applied to secure the plication. This is mostconveniently accomplished while approximating tool assembly 508 is heldin place by the operator to maintain the tissue in a stable, foldedconfiguration. In one embodiment, a separate interventional instrumentmay be introduced through a separate trocar, and its distal tip may bepositioned immediately adjacent approximating tool assembly 508. Thisinstrument is then actuated to apply a fastener directly into and acrossthe shoulders of the approximated tissue forming the tissue fold,thereby securing the plication. In this embodiment illustrated in FIG.6A, a system 600 of the present invention comprises two separatehandheld devices, each device capable of being actuated using controlslocated at their respective proximal handle assemblies. A first device620 incorporates an approximating tool assembly 625 which may besubstantially similar to approximating tool assembly 508, describedabove, at its distal end, and a second device 640 incorporates afastening tool assembly 645 at its distal end, capable of applying afastener to the tissue fold to secure the plication. A wide variety of asuitable fasteners are known to those skilled in the art and may besuitably be used as fasteners within the broad scope of the presentinvention. Exemplary fasteners comprise, for example, sutures, box-typestaples, U-shaped or hemispherical fasteners, helical fasteners, clips,tacks, wall anchors, t-tags, and the like. A commercially availablelaparoscopic stapler, suturing device or tack applicator may be used tosecure the tissue fold.

Accordingly, the laparoscopic interventional stapler shown in FIG. 6Acomprises an elongate tubular shaft 650 having at its proximal end ahandle assembly 655 containing user controls, actuation mechanisms, andso on, and having at its distal end a fastening tool assembly 645, whichincorporates mechanisms known in the art for feeding, deploying, formingand applying to the target tissue a plurality of fasteners. Thesefasteners are most commonly made from stainless steel, titanium or NiTi,although other materials may also be used (e.g. other biocompatiblealloys, polymers, bioabsorbable materials, and the like). Typically, aplurality of such staples would be provided within a disposable (i.e.single patient use) cartridge that is loaded at the distal end of thedevice, allowing multiple staples to be placed consecutively by theoperator without removing the device from the patient.

FIG. 6B shows a close up view of the distal ends of device 620 anddevice 640, indicating the preferred relative positioning ofapproximating tool assembly 625 and fastening tool assembly 645,respectively, according to one embodiment of the present invention. Inthis view, approximating tool assembly 625 has previously been deployed,the tissue has been engaged, and the extendible members have beenretracted (these steps being carried out e.g. as described in FIG. 5),in order to create tissue fold 660. Shoulders 665 of tissue fold 660 areapproximated near the distal tip of approximating tool assembly 625, andare held in position, ready for the tissue fastener to be applied byfastening tool assembly 645. The cross sectional view of FIG. 6C shows aclose up of the distal tip of fastening tool assembly 645. In thisexample, a box-type staple in the pre-deployed state 670 is shown loadedwithin the within fastening tool assembly 645. Prior to applying thestaple, fastening tool assembly 645 is positioned such that staple legs671 of box-type staple in pre-deployed state 670 are positionedsubstantially perpendicular to, and in contact with, shoulders 665 ofthe tissue fold. When the surgeon fires the stapler using actuationmeans provided within the proximal handle assembly, extendible pistons642 extend distally, deforming staple legs 671 around stationary anvil644 and thereby reconfiguring the box-type staple into deployed state675 as it is ejected from the device. As the staple is deployed, itpenetrates the tissue and simultaneously pulls opposing tissue shoulders665 toward one another, as shown. Note in this example that the box-typestaple in deployed state 675 engages only the outermost layers ofgastric tissue, i.e. serosal layer 535 and/or the muscularis tissuelayers (not shown), and that there is no penetration through the gastricwall, which preserves the mucosal tissue layer 540 intact. FIG. 6Dschematically illustrates a plication being secured using severalconsecutively repeated applications of the above described procedure.Approximating tool assembly 625 and fastening tool assembly 645 areshown, along with a multiplicity of individual box-type staples in thedeployed state 675 that have been applied and which are arranged in asubstantially continuous row extending along the length of tissueshoulders 665 to secure plication 690 projecting into thegastrointestinal space. The depth 680 below the surface and spacing 685between the individual staple placements may be selectively controlledby the operator.

In another embodiment of the present invention, the tissue approximatingand fastening functions described above requiring the use of twoseparately operable handheld interventional instruments are combinedinto a single multi-functional device having one or more integratedtools capable of invaginating and approximating tissue to create atissue fold, as well as one or more integrated tools for applyingfasteners to secure the plication. By combining these functionsconveniently in a single handheld device, the overall procedure issimplified, and it can be performed without requiring extensive operatortraining Furthermore, the need for one laparoscopic access port iseliminated, which provides a significant advantage.

FIGS. 7A-7H illustrates such an integrated device and its operation,according to one embodiment of the present invention. Device 700comprises an elongate tubular member 702 having internal working channel704 and handle assembly 706 positioned at the proximal end. At thedistal end of device 700 is multi-functional tool assembly 708, shown inthe collapsed (i.e. pre-deployment or fully retracted) state in FIG. 7A.It is generally desirable that the outer diameter of elongate tubularmember 702 be as small as possible, preferably 20 mm or less, morepreferably 15 mm or less and, in some embodiments, 12 mm or less. Theembodiment illustrated in FIG. 7A, illustrates actuating mechanisms usedto operate the device, namely first trigger 710, second trigger 711,slider 712, and plunger 714 provided in connection with handle assembly706. Also shown is rotating collar 716 that allows the orientation ofhandle assembly 706 to be independently adjusted by the user relative tothe orientation of approximating tool assembly 708.

A close up cross sectional view of the distal end of device 700 is shownin FIG. 7B, illustrating details of multi-functional tool assembly 708in the collapsed state. Multi-functional tool assembly 708 combinessubstantially similar structural and functional elements as previouslyillustrated in and described with reference to FIGS. 5 and 6.Accordingly, in this configuration, located along longitudinal axis 718of working channel 704 are two (or more) extendible members 720, and(optional) pushing member 722, each being operatively connected toactuating mechanisms accessible to an operator at handle assembly 706.Each of the extendible members 720 is configured at its distal end witha distal tip 724, and each distal tip 724 incorporates one or moretissue engagement mechanisms whose working function is to controllablyand selectively grasp, grab, grip, pierce, hold or otherwise engagetissue. In the example shown, distal tips 724 incorporate tissue hooks726. Box-type staples in pre-deployed state 730 are loaded into workingchannel 704 and are configured (using, for example, guide channels and aspring loading mechanism) to slidably move toward the distal end ofmulti-functional tool assembly 708 and into the pre-fire position 731 asstaples are sequentially ejected from the device. Pistons 732 arepositioned at the distal end of shaft 733, and, along with stationaryanvil 734, are used to deform staple legs 735 and thereby reconfigureand eject the staples when the device is actuated by the user, asdescribed below.

FIG. 7C illustrates a close up view of multi-functional tool assembly708 having extendible members and tissue engagement mechanisms in theextended state, i.e. after being deployed by the operator. In theembodiment illustrated, plunger 714 is operatively connected toextendible members 720, such that when plunger 714 is pushed into handleassembly 706, extendible members 720 move distally along longitudinalaxis 718, and thereby extend outwardly from working channel 704 andbeyond the end of elongate tubular member 702. During deployment to theextended state, each of extendible members 720 is positioned such thatdistal tips 724 are spaced apart from one another and positioned onopposite sides of longitudinal axis 718. In the example shown,extendible members 720 have a flattened cross sectional configuration toincrease lateral stiffness and prevent undesirable out-of-plane bendingduring deployment. Distal tips 724 of the extendible members 720 maycomprise multiple tissue hooks 726, which facilitate secure tissueengagement and help to prevent undesired out-of-plane bending ofextendible members 720 during deployment. Both the longitudinalpositioning 719 and spacing 721 of arm tips 724 may be selectablycontrolled by the user to facilitate the desired positioning of tissueengagement members 726 and the subsequent size and position of thetissue plication formed by approximating the tissue.

Device 708 additionally incorporates pushing member 722, which isoperatively connected to slider 712, such that when slider 712 is pushedfrom its proximal (fully retracted) position, the distal end of pushingmember 720 moves along longitudinal axis 718, thereby extending out ofworking channel 704 a user selectable distance 705 beyond the end ofelongate tubular member 702. The pushing member facilitates invaginationand folding of the tissue between the engaged portions and may,additionally, function to disrupt the serosal tissue surface, orfacilitate application of a tissue bonding promoter, as described above.Operation of the pushing member may be independent of, or coordinatedwith, extension and retraction of the extendible members and tissueengagement mechanisms.

The steps of deploying device 700, engaging tissue, and invaginating andapproximating tissue to create a tissue fold are substantially similarto what was previously described with reference to FIGS. 5D-5F. For thesake of clarity, these sequential steps are again illustrated in FIGS.7D-7F with reference to operation of multi-functional tool assembly 708.After the tissue has been approximated and the fold has been created,device 700 is positioned in a suitable location for the subsequent stepof applying one or more fasteners to secure the plication. Accordingly,similar to corresponding FIG. 6C, FIG. 7G illustrates the distal portionof device 700 after the device has been actuated from within handleassembly 706 using a second trigger 711, which is operatively connectedto extendible shaft 733. The actuation, as described previously, formsand ejects a box-type staple, reconfiguring it by deformation from thepre-deployed state 730 to the deployed state 736, and securelyimplanting the staple within the tissue as described previously. Thisresults in penetration and pulling together of the opposing tissueshoulders 765, which thereby secures the created tissue plication 790projecting into the gastrointestinal space. Tissue hooks 726 may then beoperatively disengaged from the tissue using a slight forward actuationof plunger 714 located within handle assembly 706, after whichextendible members 720 may be completely retracted back into the shaftof the device by full reverse actuation of plunger 714. Pushing member722 may also be completely retracted back into the device, using reverseactuation of slider 712. The serosal tissue layer may be treated topromote bonding during manipulation of the pushing member, as discussedpreviously. The next in line pre-loaded staple in the pre-deployed state730 automatically (for example, via spring pressure) moves into thepre-fire position 731, and the device is therefore fully prepared andready for repeating the entire sequence at the next tissue locationselected by the operator, as shown in FIG. 7G.

As illustrated in FIG. 7H (substantially similar to FIG. 6D), afterrepeating the procedural steps described above using multi-functionaltool assembly 708, a plurality of staples in the deployed state 736 areimplanted into and across tissue shoulders 765, securing plication 790projecting into the gastrointestinal space. One or more such plicationsmay be produced in this manner, each having the desired length, depth,etc., and each having a selectable number of implanted fasteners,fastener depth, fastener-to-fastener spacing, and so on, as previouslydescribed. Using the devices of the present invention in this manner,the operator is therefore able to achieve the desired gastric reductionlaparoscopically and without ever needing to fully penetrate the gastricwall or otherwise compromise the internal mucosal tissue layer.

FIG. 8 illustrates an example device according to another embodiment ofthe present invention. An overview of device 800 is shown in FIG. 8A inthe pre-deployed configuration, and in FIG. 8B device 800 is shown inthe deployed configuration. Device 800 consists of handle assembly 805positioned at the proximal end, tool assembly 810 positioned at thedistal end, and elongate tubular shaft assembly S15 connecting handle 20assembly 805 and tool assembly 810. Handle assembly 805 is operativelyconnected to tool assembly 810 and provides for actuation of the deviceby the user, as will be described in detail below. In the example shown,tool assembly 810 includes two moveable arms 818 that are configured aslongitudinal bands having rectangular cross section that are operativelyconnected to shaft assembly 815. As shown in FIG. 8A, in thepre-deployed (i.e. fully retracted) position, moveable arms 818 are heldsubstantially within shaft assembly 815, with only the distal ends ofmoveable arms S1S visible and exposed at the distal end of device 800.As shown in FIG. 8B, in the deployed configuration handle assembly 805has been actuated, as will be described below, and moveable arms 818thereby extend out of and away from the distal end of shaft assembly815, in the desired position for engaging tissue.

FIG. 9A shows a detailed cross section view of handle assembly 805,along with a portion of the proximal end of connected tube assembly 815.Tube assembly 815 consists of outer tube 820, actuating tube 822 andinner tube 824 which are co-axially arranged along longitudinal axis825. In this embodiment, outer tube 820 is designed and configured to beinserted into a trocar placed through the abdominal wall when performinga laparoscopic procedure. It is therefore preferable that outer tube beas small in diameter as is practicable to allow for use of the smallestpossible laparoscopic incision and trocar size. Outer tube 820 ispreferably between 2 mm and 20 mm in diameter and between 5 cm and 100cm in length, more preferably between 2.5 mm and 18 mm in diameter andbetween 12 cm and 70 cm in length, and most preferably between 3 mm and12 mm in diameter and 15 cm and 65 cm in length.

Actuating tube 822 is inserted into the proximal end of outer tube 820and terminates at its distal end at a location proximally from thedistal end of outer tube 820. In this manner actuating tube 822 iscapable of sliding longitudinally within outer tube 820 from itsproximal most (i.e. pre-deployed) position to a distal most (i.e.deployed) position. The outer diameter of actuating tube 822 is slightlyless than the inner diameter of outer tube 820 such that a small gapexists between the tubular walls. This substantially eliminates slidingfriction between actuating tube 822 and outer tube 820, except at asmall area of intimate frictional contact established between the tubes(described below). Inner tube 824 fits within actuating tube 822 and isalso fixedly connected to outer tube 820 near the distal end of device800, as described below. Located inside inner tube 824 is workingchannel 826 within which proximal gasket 827 is mounted. As will bedescribed later, the purpose of proximal gasket 827 is to support andfrictionally hold in position a complementary medical device that mayoptionally be inserted within working channel 826 of inner tube 824during operation of device 800, as will be described later.

Tube assembly 815 therefore consists of a concentric tube configurationwhere actuating tube 522 is slidably positioned between the walls ofouter tube 820 and inner tube 824, which are fixedly connected to oneanother at their distal ends. Outer tube 520, actuating tube 822 andinner tube 824 are all manufactured from suitable biocompatiblematerials, typically polymers and/or metals, that are known to thoseskilled in the art for common usage in either re-usable or singlepatient use medical devices. The tubes are 30 typically substantiallyrigid, although they may be provided with a designed degree of elasticflexibility, or they may optionally incorporate articulation means (e.g.using mechanical methods well known in the art) along their length,which can prove useful in certain surgical situations.

Fixedly connected to the proximal end of outer tube 820 is distal grip828, and fixedly connected to the proximal end of actuating tube 822 isproximal grip 830. When proximal grip 830 is moved toward distal grip828 by the operator, actuating tube 822 slides distally between thewalls of outer tube 820 and inner tube 824. Likewise, when proximal grip830 is moved away from distal grip 828, actuating tube 822 slidesproximally between the walls of outer tube 820 and inner tube 824.Distal grip 828 and proximal grip 830 can have the same or differentshape, and are designed based on ergonomic considerations to allow easygripping and secure holding by the hand of the operator, typically withthe forefingers positioned on distal grip 828 and thumb positioned onproximal grip 830.

It should be recognized by those skilled in the art that various othertypes of grips may be used according to the present invention to allowthe operator to affect the same type of relative sliding motion betweenactuating tube 822 and outer tube 820. For example, knobs, rings,grooves, levers, handles, and the like may be used. Distal grip 828 andproximal grip 830 may be produced from any polymeric or metallicmaterial commonly known in the art for usage in either re-usable orsingle patient use medical devices. In other embodiments that will beobvious to those skilled in the art (not shown), one or both grips maybe replaced by other means for engaging outer tube 820 and actuatingtube 822, wherein said engagement means may be operatively connected toan alternative actuation mechanism (e.g. trigger, lever, pi votablehandle, scissors grip, or the like) that may optionally be positionedfarther away from the proximal end of tube assembly 815. In this manner,when said alternative actuation mechanism is operated by the user,substantially the same type of longitudinal sliding motion betweenactuation tube 822 and outer tube 820 is effected. Said alternativeactuation mechanisms may be operated by user hand power, or they may bepowered partially or entirely using an external power source such as anAC or DC electromagnetic motor, compressed gas, ultrasonic motor, or thelike.

Located between distal grip 828 and proximal grip 830, and positionedoutside actuating tube 822 is spring 832. Spring 832 is held in placeby, and pushes against, distal grip 828 at recess 834, and also pushesin the opposite direction against the distal most surface 835 ofproximal grip 830. Spring 832 is designed to operatively maintain aspecified biasing force along longitudinal axis 825 that acts to pushactuating tube 822 toward its proximal most position relative to theposition of outer tube 820 when the device is in the pre-deployedconfiguration. When spring 832 is in its maximum allowable expandedstate (i.e. device 800 is in the pre-deployed configuration), flange 836located at the proximal end of deployment tube 824 comes into contactwith the bottom of recess 838 located on the proximal side of proximalgrip 830, thereby limiting the extent of proximal motion of actuatingtube 822.

FIG. 9B illustrates a the detailed cross section view of handle assembly805 after actuation as described. Movement of proximal grip 830 towarddistal grip 828 thereby compresses spring 832 as actuating tube 822slides distally between outer tube 820 and outside of inner tube 824. Asshown, the proximal end of inner tube 824 then moves within recess 838in proximal grip 830. As spring 832 is compressed, additional elasticenergy is stored within the spring that is later released and used toreturn (or substantially assist in returning) proximal grip 830 to itsproximal most (pre-deployed) position, thereby also tending to moveactuating tube 822 back to its proximal most (pre-deployed) position(FIG. 9A).

FIG. 10 shows a detailed cross section view of a portion of shaftassembly 815. Shaft assembly 815 consists of outer tube 820, actuatingtube 822 and inner tube 824. As described previously, actuating tube 822is slidably positioned between the walls of outer tube 820 and innertube 824. Fixedly connected to the distal end of actuating tube 822 isbushing 840. The inside diameter of bushing 840 is the same as theinside diameter of actuating tube 822 such that inner tube 824 passesthrough without restriction. At least a portion of bushing 840 has anoutside diameter that is sized to substantially make frictional slidingcontact with the inner wall of outer tube 820. Bushing 840 therebyensures that actuating tube 822 remains centrally aligned alonglongitudinal axis 825 during actuated sliding, while minimizingfrictional forces and therefore minimizing the overall forces requiredfor actuating device 800. Bushing 840 is further configured withengagement means for fixedly connecting to the proximal ends 819 of eachof two moveable arms 818, such that moveable arms 818 are positionedbetween the walls of outer tube 820 and inner tube 824. This allowsmoveable arms 818 to move distally and proximally inside outer tube 820along with the actuated distal and proximal sliding of actuating tube822. In the example shown, bushing 840 is produced from molded polymer,and moveable arms 818 are embedded directly into the wall of bushing 840during manufacture, for example by insert injection molding.Alternatively, various other methods known to those skilled in the artmay be employed to fixedly connect the proximal ends of moveable arms818 to bushing 840, such as keyed recesses, threads, rivets, welds,adhesives, and the like. Bushing 840 is also optionally configured witha means for guiding and maintaining a specified fixed rotationalalignment between actuating tube 822 and outer tube 820 during sliding.For example, bushing 840 may be configured with a protruding tab (notshown) on its outer surface that is designed to fit within alongitudinal groove (not shown) located on the inside wall of outer tube820. This allows longitudinal sliding of actuating tube 822, whilepreventing undesirable rotational motion relative to outer tube 820 thatcan damage moveable arms 818 or otherwise make actuation of device 800difficult.

FIG. 11 shows a close up section view of tool assembly 810 located atthe distal end of device 800. FIG. 11A illustrates the pre-deployedconfiguration. As described previously, moveable arms 818 are fixedlyattached to the distal end of actuating tube 822 via bushing 840 and arethereby configured to move longitudinally in a forward (distal) orreverse (proximal) direction, corresponding to the actuated motion ofproximal grip 830 relative to distal grip 828.

Moveable arms 818 can be made from any substantially flexible materialand can be produced having a wide variety of shapes. Preferably moveablearms 818 have a noncircular cross section in order to minimize spacerequirements in the pre-deployment configuration, while also providingsufficient lateral rigidity (i.e. significant resistance to undesirableout of plane bending and rotation when in the deployed configuration).In device 800, moveable arms 818 have a rectangular cross section asshown, however it should be obvious to those skilled in the art thatother cross sectional shapes can be used to provide the samefunctionality, for example, square cross sections, triangular crosssections, arcuate cross sections, hemispherical cross sections, andcombinations of the foregoing may be used. The cross sectional shape,physical dimensions, mechanical properties, and so on, of moveable arms818 may also be designed having variations along their length in orderto provide improved deployment, tissue engagement or refractioncharacteristics.

Each of said moveable arms 818 is configured at its distal end with armtip 842, wherein each said arm tip 842 includes one or more elementswhose working function is to controllably and selectively grasp, grab,grip, pierce, hold or otherwise engage tissue. In the example shown, armtips 842 incorporate sharpened tissue hooks 844. A variety of otherconfigurations and mechanisms are possible within the scope of thepresent invention for engaging tissue at the distal end of moveable arms818. For example, teeth, barbs, jaws, graspers, forceps, clamps and thelike may be used, the choice of which may depend upon the nature of thetissue to be engaged, desired depth of penetration, and so on. In thepredeployed configuration (FIG. 11A) moveable arms 818 are drawn upinside shaft assembly 815, slidably positioned in the gap between theouter wall of inner tube 824 and the inner wall of outer tube 820. Armtips 842 are positioned adjacent to one another substantially close tothe distal end of device 800.

Inner tube 824 has working channel 826 therewithin that provides a meansfor inserting and holding in position a variety of interchangeable andcomplementary tools (e.g. a device for manipulating or treating tissue,a device for applying fasteners, etc.) that, along with device 800,further comprise the systems of the present invention. Working channel826 is designed to accept any instrument having a diameter that issmaller and within a specified size range. In the embodiment shown, forexample, working channel 826 is designed to accept an instrument havinga diameter from approximately 3.5 mm to 5.5 mm. Located inside workingchannel 826 are one or more retaining means capable of holding theinserted instrument in a desired longitudinal position, preferablyallowing said position to be adjusted by the user prior to or duringuse. In the example shown, the retaining means is provided as anproximal gasket 827 (FIG. 9A) and distal gasket 858 (FIG. 11A) situatedand held within retaining grooves (not shown) positioned along theinside wall of inner tube 824. Proximal gasket 827 and distal gasket 858frictionally engage with the outer diameter of the inserted instrumentto hold it in position. A specified amount of force may be applied thatis sufficient to overcome the friction, and in this manner the positionof the inserted instrument may be slidably adjusted. Various other meansknown to those skilled in the art may be employed to achieve the sameresults, for example, compression fittings, cams, clamps, twist locks,and so on, may be used.

Also located inside working channel 826 are optional alignment meansthat may engage with optional alignment features provided on the outsideof an inserted instrument, to ensure a desired alignment of the insertedinstrument is maintained relative to the orientation of device 800. Inthe example shown, alignment groove 860 located within the inside wallof inner tube 824 is configured to slidably engage with a suitablydesigned male feature (e.g. a protruding tab, nipple, pin, or the like)that may optionally be included on the exterior of the shaft of themedical device to be inserted. This allows for keyed insertion andlongitudinal sliding to take place, but prevents undesirable rotation ofthe inserted device inside working channel 826 once inserted. Thissystem feature may be important in a variety of situations, for example,a fastener applicator inserted into working channel 826 may need to bealigned in a specific orientation relative to the position of moveablearms 818 in order to properly secure the created tissue fold and producea plication, according to the methods of the present invention. When itis desirable for the surgeon to change the overall orientation of theinstrument relative to the target tissue, tube assembly 815 may beconfigured to rotate to any user selectable orientation relative tohandle assembly 805; in such a configuration, the inserted instrumentrotates along with tube assembly 815 thereby maintaining properfunctional alignment of the instruments regardless of the user's handposition.

At the distal end of device 800 is end cap 850 which matingly connectsto the inner wall of outer tube 820 and the outer wall of inner tube824, thereby serving to fixedly connect these components together. Endcap 850 further incorporates means for supporting, guiding andmaintaining proper alignment of moveable arms 818 during actuatedsliding, corresponding to the desired alignment between actuating tube822 and outer tube 820. In the example shown, end cap 850 is producedfrom molded polymeric material and includes longitudinal slots 852substantially matching the rectangular cross section of moveable arms818 and through which moveable arms 818 are inserted during assembly.

Fixedly or removeably connected to end cap 850 is optional tissueconfiguration element 855 that is intended to guide, position and shapetissue that is approximated during use of device 800 as moveable arms818 are retracted and the engaged tissue is drawn close to the distalend of tube assembly 815. In its simplest form, optional tissueconfiguration element 855 is provided as a pair of arms extendingdistally from end cap 850, defining a U-shape or V-shape (the exampleprovided in FIG. 11B) into which tissue is drawn when moveable arms 818are fully refracted after engaging tissue. Alternatively,cylindrical-shaped members, cone-shaped members, or the like, can beprovided, as long as tissue can be drawn up against or inside thecomponent upon refraction of moveable arms 818. Optional tissueconfiguration element 855 is beneficial for ensuring that theapproximated tissue is provided in optimal configuration for theinsertion of a retaining fastener that is used to secure a createdtissue fold to produce a plication, according to the methods of thepresent invention. For example, optional tissue configuration element855 may help ensure that tissue planes on both sides of the approximatedtissue interface are automatically aligned substantially parallel to,and centered around, longitudinal axis 825 of device 800. Further,optional tissue configuration element 855 may be designed such thattissue drawn or pushed inside is thereby compressed a specified anddesired amount, preferably in a direction perpendicular to theapproximated tissue interface. Such tissue alignment and compressionprior to fastening may improve the accuracy of fastener placement, mayenhance the strength and durability of the plication produced, and mayallow a simpler fastener design and smaller fastener applicator to beused compared to the prior art, as will be described below. A variety ofinterchangeable optional tissue configuration element designs may beuseful in different circumstances, or sometimes it may be desirable toremove it altogether, therefore it is preferable that optional tissueconfiguration element 855 be removably connected to the distal end ofcap 850 using a thread connection, snap connection, bayonet connection,or the like.

As described previously, device 800 is actuated by moving proximal grip830 toward distal grip 828, thereby compressing spring 832. This causesactuating tube 822 to slide distally between outer tube 820 and innertube 824, and moveable arms 818 thereby extend beyond the distal end oftube assembly 815, as shown in FIG. 11B. Device 800 may be held in thedeployed configuration manually (using hand force supplied by the user)or, alternatively, a latch, cam, compression fitting, twist lock orother mechanical means known to those skilled in the art may be providedto temporarily maintain the deployed configuration after the user'shands are removed.

In the deployed configuration, each of moveable arms 818 arereconfigured such that arm tips 842 are separatively spaced andpositioned on opposite sides of longitudinal axis 825. Both thelongitudinal positioning 862 and spacing 864 of arm tips 842 areselectably controlled by the user to facilitate the desired subsequenttissue engagement, up to the limit of full deployment when proximal grip830 has been pushed together against distal grip 828 to compress spring832 to the maximum allowable amount. Devices of the present inventionmay be designed to approximate tissue over a variety of size ranges,where longitudinal positioning 862 and spacing 864 are primary designfactors that can be adjusted based on the intended medical mission. Foruse according to the methods of the present invention, it has been foundthat longitudinal positioning 862 is preferably between 0.5 cm and 20cm, more preferably between 1 cm and 15 cm, and most preferably between2 cm and 12 cm. Similarly, spacing 864 is preferably between 1 cm and 30cm, more preferably between 1.5 cm and 20 cm, and most preferablybetween 2 cm and 15 cm.

During deployment of device 800, moveable arms 818 are designed to bereconfigured from a collapsed state to an expanded state to prepare thedevice for subsequent tissue engagement steps. In one preferredembodiment, moveable arms 818 are designed to be reconfigured from thecollapsed state to the expanded state in a self-actuating manner,automatically achieving the desired tissue engagement configuration whenextended out of tube assembly 815. Such self-actuating motions can beachieved by various methods known in the art. For example, in onepreferred embodiment of the present invention, moveable arms 818 areproduced from a highly elastic material (e.g. spring steel, hardenedstainless steel, superelastic NiTi alloy, superelastic polymer, or thelike) and are formed during manufacturing into the desired finaldeployed shape by mechanical and/or thermomechanical processing meansknown in the art. Moveable arms 818 are then spring biased (i.e.mechanical potential energy is stored, similar to a pre-loaded spring)by elastically deforming and loading them into tube assembly 815 tothereby provide the device in its pre-deployed state. As moveable arms818 are then pushed out of tube assembly 815 during deployment, thestored energy is released and moveable arms 818 automatically return tothe predetermined shape, being the shape of the deployed state (FIG.11B) desired for subsequent tissue engagement when brought into contactwith the tissue surface.

The operation of device 800 will now be explained in greater detail withreference to the steps used in performing the procedure of the presentinvention, illustrated in FIG. 12. FIG. 12A shows device 800 in thedeployed configuration and positioned substantially perpendicular to thetissue surface 1205 to be approximated. Arm tips 842 are brought intocontact with the tissue such that tissue hooks 844 are able toeffectively penetrate the tissue surface and thereby engage the tissueat two separate locations 1210 and 1215. As illustrated, the locationsof tissue engagement are determined by the shape and dimensions ofmoveable arms 818, arm tips 842 and tissue hooks 844 when in thedeployed configuration, which substantially determines the size of thetissue fold that will be created upon approximation of the engagedtissue locations.

After tissue is engaged by tissue hooks 844 on arm tips 842, proximalgrip 830 is subsequently released and the elastic energy stored incompressed spring 832 produces a longitudinal force 1220 that retractsactuating tube 822 and connected moveable arms 818 proximally toward theoriginal (pre-deployed) configuration. Depending on the spring forceavailable (which may be fixed by the design of device 800 and/or may beadjustable by the user) relative to the required forces forapproximating the tissue, proximal grip 830 is moved proximally relativeto distal grip 828 using an assisting hand force provided by the user,if desired or necessary. As retraction of moveable arms 818 back intotube assembly 815 begins, tissue engagement locations 1210 and 1215 aregradually pulled inward toward longitudinal axis 825, as illustrated inFIG. 12A. FIG. 12B shows the situation upon continued retraction ofmoveable arms 818, where proximal grip 830 is moved further proximallyand tissue engagement locations 1210 and 1215 are positioned closer tolongitudinal axis 825.

Also shown in FIG. 12A and FIG. 12B is the use of optional pushingmember 1222, which is inserted into and extends distally from workingchannel 826 a user selectable distance, thereby controllably pushingagainst tissue between tissue engagement locations 1210 and 1215.Optional pushing member 1222 is held slidably within tube assembly 815by proximal gasket 827 and distal gasket 858 (not shown) and thereforebecomes a component of the system of the present invention that ensuresthe desired invaginated tissue fold is created during approximation,according to the methods of the present invention. Optional pushingmember 1222 may further incorporate surface features 1224, whosefunction will be described below.

As illustrated in FIG. 12C, upon complete proximal movement of proximalgrip 830 back to its pre-deployed position, moveable arms 818 arecompletely retracted within tube assembly 815 and only arm tips 842 arevisible. Tissue engagement locations 1210 and 1215 are therebyapproximated substantially near the distal end of tube assembly 815,creating an invaginated tissue fold 1225 extending distally away fromthe device substantially along longitudinal axis 825. Optional pushingmember 1222 may either be left in place inside invaginated tissue fold1225 until retraction is completed (as shown in FIG. 12C) or it may bewithdrawn any time prior to completing creation of invaginated tissuefold 1225 by the user, if not further needed. As illustrated in FIG.12C, in the case of approximating stomach tissue to create aninvaginated tissue fold projecting into the gastrointestinal cavityaccording to the methods of the present invention, tissue surface 1205comprises the external serosal tissue layer, and the opposing serosaltissue surfaces inside invaginated tissue fold 1225 are brought togetherand substantially intimate serosa-to-serosa contact is achieved,preferably without forming wrinkles, bunches, gaps, or the like, andwithout penetrating the internal mucosal tissue layer 1230.

According to one embodiment of the present invention, it is optionallydesirable to selectively and therapeutically treat the serosal tissuelayer to promote a healing response across the approximated serosaltissue surfaces within the produced plication. In one embodiment, theoptional serosal treatment may be carried out before the tissue isapproximated to form the tissue fold, as a separate tissue surfacepreparation step. For example, an independent surgical instrumentdesigned for treating the serosa to promote a healing response may beintroduced into the abdominal cavity through the same trocar used fordevice 800, or through a different trocar.

In another embodiment of the present invention the optional serosaltreatment is carried out during creation of invaginated tissue fold 1225by mechanically disturbing and disrupting the thin layer of mesothelialcells that form the outermost covering of the serosa. Since the layer ofmesothelial cells covering the serosa is quite thin and fragile, it iseasily disrupted, e.g. when an instrument is scraped, dragged orotherwise frictionally moved across the surface of the tissue.Consequently, the desired optional serosal treatment may be accomplishedwith the assistance of device 800 in various ways. For example, withdevice 800 in the pre-deployed configuration, the distal end of tubeassembly 815 itself may be used to mechanically abrade the serosa.Alternatively, the distal tip and/or lateral surfaces of optionalpushing member 1222 may similarly be used. To further aid in ensuringadequate serosal treatment occurs, optional pushing member 1222 mayfurther be optionally configured with various means for treating theserosa. In one embodiment, as illustrated in FIG. 12, optional pushingmember 1222 further incorporates surface features 1224 located on itsdistal end that are used to disturb and disrupt the serosal tissuesurface. As will be obvious to those skilled in the art, a wide varietyof such surface features and arrangements may be used to accomplish thedesired serosal treatment, for example, ridges, bumps, bristles, teeth,scales, serrations, and the like may be provided. In one approach,serosal treatment may be accomplished prior to deploying device 800 toengage tissue by extending optional pushing member 1222 distally andmoving it across substantially the identified area of serosal tissue tobe included within the tissue fold in a sweeping or painting type ofmotion. Alternatively, because the lateral surfaces of optional pushingmember 1222 will necessarily contact and slide across the opposingserosal tissue surfaces inside the tissue fold when optional pushingmember 1222 is withdrawn after approximation is complete (see FIG. 12C),it can be used to disrupt at least a substantial portion of the serosaltissue surface during normal operation of device 800, thereby savingprocedural time. In this case, surface features 1224 ensure more uniformand consistent serosal treatment, leading to a more effective healingresponse and a stronger serosa-to-serosa tissue bond.

According to the methods of the present invention, once the desiredinvaginated tissue fold projecting into the gastrointestinal cavity hasbeen created as described above, securing means are then applied inorder to produce a plication. While a variety of prior art fasteners andfastener applicators could conceivably be used for this purpose, variouslimitations and shortcomings have been encountered. In general, priorart surgical methods involving either cutting of the gastrointestinallumen or the creation of gastrointestinal tissue folds rely upon theplacement of surgical staples or other fasteners through the stomachwall. This necessarily involves the fastener penetrating at least themucosal and muscularis tissue layers. Unfortunately, the mucosal andmuscularis tissue layers are known to be relatively weak and unreliablefor securely holding fasteners, and the placement of fasteners throughthese tissue layers often results in complications or lack of long-termdurability. For example, prior art fasteners may produce chronic tissueirritation or result in tearing of tissue near the fastener penetrationsites, may undergo post-surgical migration or dislodging, and may failto heal and/or result in life threatening leakage at transgastricpenetrations.

The tissue retaining fasteners of the present invention overcome theabove stated problems. These fasteners are designed to be placedextragastrically into gastrointestinal tissue folds created using thetissue approximating devices of the present invention. In someembodiments placement of the tissue retaining fasteners may involvecomplete penetration through the stomach wall, whereas in otherpreferred embodiments the fasteners do not involve complete transgastric penetration. In either case, the tissue retaining fasteners ofthe present invention are preferably designed to engage and securelyhold the thin, tough serosal layer covering the exterior of thegastrointestinal lumen. In this manner, these inventive tissue retainingfasteners thereby provide substantially improved strength, reliabilityand durability to the plication produced, while avoiding the seriousrisks associated with transecting the stomach wall, compressing themuscularis tissue layers, or excessively compromising the internalmucosal layer. According to the methods of the present invention,optional treatment of the serosal tissue to promote a healing responseresults in the formation of a strong serosa-to-serosa bond across theapproximated tissue boundary within the plication, providing additionallong-term structural support to the extragastrically placed fasteners.As such, the tissue retaining fasteners of the present invention mayoptionally be produced from a bioabsorbable or dissolvable materialdesigned to disappear after the strong serosa-to-serosa bond has formed,further minimizing the risks associated with long-term fastenerimplants.

The tissue retaining fasteners of the present invention are designed toaccurately penetrate, engage and securely hold invaginated tissue foldscreated by approximating devices of the present invention, therebyproducing strong and durable plications. Minimally invasive fastenerapplicators of the present invention (described below) are provided thatare designed to deliver and deploy these tissue retaining fasteners byoperating in conjunction with the approximating devices of the presentinvention. The approximating devices, fasteners and fastener applicatorsof the present invention, taken together, comprise systems of thepresent invention.

According to one embodiment of the present invention, a tissue retainingfastener is shown in FIG. 13. Fastener 1300 generally exhibits au-shapehaving cross member 1305 and at least two substantially parallel tissuepenetrating projections 1310 connected near opposite ends of said crossmember and extending longitudinally therefrom. Tissue penetratingprojections 1310 have length 1312. Each of said tissue penetratingprojections has a sharpened tip 1315 positioned at its distal end thatpromotes penetration through the serosa and into the underlyingmuscularis tissue, lowering the required insertion forces. The fastenershown in FIG. 13 has a round cross section such as, for example, wouldbe obtained by producing these fasteners from cut and bent wire or rodstock. In this embodiment, the diameter of the wire or rod used tomanufacture the fastener is preferably between 0.05 mm and 2 mm, morepreferably between 0.1 mm and 1.75 mm, and most preferably between 0.2mm and 1.5 mm. In other embodiments different cross sectional shapes maybe used, such as square cross sections, rectangular cross sections,semicircular cross sections, and so on. The fastener may be manufacturedusing any common production method and may be made from any suitablebiocompatible material known to those skilled in the art of surgicalstaples and tacks, including, for example, metals such as stainlesssteel, titanium, and NiTi, or various structural polymers. The fastenersmay also preferably be produced from bioabsorbable or dissolvablematerials designed to have a limited functional lifetime afterimplantation in human tissue.

Positioned on at least one tissue contacting surface of each tissuepenetrating projection 1310 is one or more tissue retention features,e.g. barb 1320 in FIG. 13. The tissue retention feature may be a point,barb, hook, tine, sharpened edge, or the like. It may be substantiallyrigid, substantially flexible, or combinations thereof. It may be formedas a part of the tissue penetrating projection during fastenermanufacture, thereby having a fixed position, or alternatively it may beconnected or joined to the tissue penetrating projection via a hinge,spring or other self-actuating feature that allows the tissue retentionfeature to change position from a collapsed configuration while in thefastener applicator to an expanded configuration (as shown in FIG. 13)prior to or during deployment into tissue. When deployed into tissue,the tissue retention feature is preferably angled at least partially inthe proximal direction to allow fastener 1300 to readily slide forwardinto tissue during deployment, while preventing backward motion of thefastener out of the tissue after deployment. As shown in FIG. 13, barb1320 is preferably located along tissue penetrating projection 1310 at aposition substantially proximal from its distal end, and the proximalend 1322 of barb 1320 preferably terminates in substantially closeproximity to the distal surface of cross member 1305. This designprovides for the most rapid and effective engagement of the thin, toughserosal layer near the tissue surface after the fastener is fullyinserted into tissue, where the serosal layer is effectively capturedbetween barb 1320 and cross member 1305. The size, shape, sharpness, andso on, of the tissue retention features are important characteristicsthat can be optimized to improve the performance of the fastener. Barbs1320 preferably extend inward (i.e. toward the approximatedserosa-to-serosa interface within the invaginated tissue fold). Thisavoids the possibility that the barbs may inadvertently penetratethrough the stomach wall or damage the mucosa, and any damage to theserosa caused by these barbs will occur within the resulting plicationand therefore serve to promote a healing esponse and beneficialserosa-to-serosa bonding across the tissue fold.

The width of fastener 1300 is established by the width 1330 of crossmember 1305. It is desirable that width 1330 be as small as possible inorder to minimize the size of the required fastener deployment deviceand to leave behind the minimum amount of material implanted within thebody, while at the same time ensuring the fastener is able to spanacross the approximated tissue boundary within the created tissue foldto reliably penetrate and engage tissue on opposing sides of said tissuefold. As shown in FIG. 14, fastener 1300 secures plication 1405projecting into the gastrointestinal space by penetrating throughserosal layer 1410 and into muscularis layer 1415, without perforatingmucosal layer 1420. Given the known thickness of human stomach tissue(typically 2-6 mm), an optimum width 1330 of cross member 1305 thereforea exists. Accordingly, cross member 1305 is preferably between 2.5 mmand 8 mm, more preferably between 3 mm and 6 mm, and most preferablybetween 3.5 mm and 5 mm. The length 1312 of tissue penetratingprojections 1310 can be varied but it is generally preferred that length1312 be less than 2× the width 20 1330 of cross member 1305.

FIG. 15 illustrates some alternative embodiments of the tissue retainingfasteners of the present invention. FIG. 15A shows fastener 1500 beingsubstantially similar to fastener 1300 (FIG. 13), however, there are twopairs of tissue retaining features positioned along issue penetratingprojections 1505. Proximal barbs 1510 provide for serosal engagement,similar to that described for barb 1320 of fastener 1300, while distalbarbs 1520 serve to also engage the underlying muscularis tissue layer,thereby providing additional strength for holding the fastener securelywithin stomach tissue. FIG. 15B shows yet another embodiment, wherefastener 1550 includes tissue retention features protruding in differentdirections from tissue penetrating projection 1555. Inward pointingbarbs 1560 are substantially similar to barbs 1320 of fastener 1300.Additional outward pointing barbs 1565 provide for extra serosalengagement surface area and can therefore increase the holding power ofthe fastener. As will be obvious to those skilled in the art, variousother tissue retention feature configurations are possible andconsidered within the scope of the present invention that help produce amore secure plication. For example, additional tissue retaining featuresmay be added that are oriented 90 degrees from the inward pointing barbsin order to also engage tissue parallel to the approximated tissueinterface within the tissue fold. Alternatively, tissue retainingfeatures may be formed completely around the tissue contact surface ofthe tissue penetrating projections, providing for tissue engagement inall directions.

FIG. 16 shows three different alternative embodiments of fasteners ofthe present invention. In these examples, the fasteners are massmanufactured easily and inexpensively from flat sheet biocompatiblematerial, for example by stamping, cutting, etching, or the like,followed by bending to produce the u-shapes indicated. In FIG. 16A,fastener 1600 consists of cross member 1605 and penetrating projections1610 having sharpened tips 1615. Each of said penetrating projectionshas at least one tissue retaining feature, in this case proximallypositioned inward pointing barbs 1620. The proximal end of barbs 1620 inthis example terminate substantially flush with the distal surface ofcross member 1605. Cross member 1605 optionally has one or more holescut through its thickness, such as hole 1625. Hole 1625 serves twofunctions. First, hole 1625 provides a means for engaging with asuitably designed fastener advancement and deployment mechanismincorporated within a compatible fastener applicator. Second, after thefastener is deployed and implanted into stomach tissue, with crossmember 1605 being placed in intimate contact with the serosal tissuelayer, hole 1625 promotes tissue ingrowth through and around thefastener after surgery, thereby increasing the retention force, holdingpower and long-term durability of the implanted fastener. Cutout 1630 isa portion of cross member 1605 having narrower cross 25 sectional areathat is positioned directly over the proximal end of barb 1620. Thisfeature, combined with the proximal termination ofbarb 1620 beingsubstantially flush with the distal surface of cross member 1605,provides a new and additional mechanism for securely engaging the thinlayer of serosal tissue, as follows. When the fastener is implantedextragastrically in stomach tissue, the thin serosal tissue layer iseffectively captured between barbs 1620 and cross member 1605. Thisserosal capturing feature prevents the serosa from disengaging from thebarbs and thereby resists fastener dislodgement, even during thesubstantial and sometimes erratic stomach motions produced during eatingand digestive processes.

FIG. 16B shows another embodiment similar to FIG. 16A, however, in theexample of fastener 1640, on each tissue penetrating projection 1610there are two proximally positioned inward pointing barbs 1650 and 1655.This increases the strength and reliability of the tissue engagement byincreasing the amount of serosal tissue captured during fastenerplacement. FIG. 16C shows yet another embodiment of a fastener similarto that of FIG. 16B, however in the example of fastener 1680, on eachtissue penetrating projection 1610 there are proximally positioned barbspointing both inward (toward) 1690 and outward (away from) 1695 theapproximated serosa-to-serosa interface within the invaginated tissuefold.

In contrast to prior art tissue fasteners, it has rather unexpectedlybeen found for the case of the extra gastric tissue fasteners of thepresent invention that improved holding force and performance isachieved when the tissue penetrating projections are made as short aspracticable. This is because it is most desirable to provide forcomplete penetration through the serosal layer and into the underlyingmuscularis layer, but otherwise not penetrate substantially deeper intothe underlying muscularis tissue than necessary as this can reduce theretaining strength of the fastener, lead to inadvertent mucosalpenetration, or result in undesirable tissue damage during or aftersurgery. FIG. 17 shows one embodiment of this type of fastener, which issimilar to fastener 1640 of FIG. 16B. Fastener 1700 consists of crossmember 1705 having hole 1710 and cutout 1715, whose functions weredescribed previously. Each of tissue penetrating projections 1720 hastwo proximally positioned inward pointing barbs 1725. Because theserosal layer is so thin relative to the overall thickness of stomachtissue, in this embodiment the length 1730 of the tissue penetratingprojections 1720 is preferably less than the twice the width 1735 ofcross member 1705. The length 1730 of tissue penetrating projections1720 is more preferably less than 1.5×, and most preferably less than 1×the width 1735 of cross member 1705.

Other novel embodiments of the fasteners of the present invention arealso illustrated in FIG. 17. For example, note that the previously shownsharpened tips located at the distal ends of the tissue penetratingprojections have been replaced with non-sharp tips 1740. While sharpenedtips minimize the forces necessary to deploy a fastener into tissue, itis also possible that normal stomach movements produced by eating ordigestion, or fastener migration after long periods of time, can causethese sharp tips to move within the tissue, thereby causing undesirablechronic irritation or damage. It is therefore often preferable to employnon-sharp tips 1740, which may be produced by dulling, smoothing,rounding or otherwise making the tips of the tissue penetratingprojections sufficiently blunt that such tissue damage is not possible.Accordingly, it has been determined that the minimum radius of curvatureon any tissue contacting surface of non-sharp tip 1740 of tissuepenetrating projections 1710 is preferably greater than 0.01 mm, morepreferably greater than 0.03 mm, and most preferably greater than 0.06mm. The use of non-sharp tips 1740 on the tissue penetrating projectionsdoes undesirably require greater fastener deployment forces, which maybe higher than forces typically available using prior art fastenerapplicators. It is therefore preferable to use the novel fastenerapplicators of the present invention (described below), which overcomesthe problem of higher fastener insertion forces and therefore allows theclinical advantages of non-sharp tips 1740 to be realized whileproviding for easy and safe fastener deployment.

As illustrated in FIG. 17, it has also been found that the shape andedges of the transition region 1745 between non-sharp tip 1740 and theuniform cross section portion of tissue penetrating projections 1720 arevery important for achieving maximum fastener retention and holdingforce. During fastener deployment, it is preferable that the tissuepenetrating projections 1720 become completely embedded in tissue withthe minimum amount of tissue cutting or tearing. It is thereforedesirable that the shape of the transition region 1745 be designed tospread and stretch tissue during penetration, without significantcutting or tearing. This is most readily accomplished using smoothtapered, conical or similar geometric shapes that gradually increase thecircumference of the cross section moving proximally from the distaltip, while avoiding the presence of any sharp edges that slide or cuttissue, i.e. the edges on any tissue contacting surface preferably havea minimum radius of curvature greater than about 0.01 mm, morepreferably greater than 0.03 mm, and most preferably greater than 0.06mm.

Yet other embodiments of fasteners of the present invention are shown inFIG. 18. These u-shape fasteners are also mass manufactured simply andinexpensively from biocompatible sheet material such as titanium,stainless steel, structural or absorbable polymers, and the like. InFIG. 18A, fastener 1800 consists of cross member 1805 and tissuepenetrating projections 1810 having sharpened tips 1820. A uniqueembodiment of these fasteners is the tissue retaining features, arms1825 in this example. Arms 1825 may be rigid and fixed in position (e.g.formed in the configuration shown by bending during fastenermanufacturing) or they may be partially or substantially elasticallydeformable and flexible (e.g. they may be retained in the plane of thefastener while held within the fastener applicator and deployed into theconfiguration shown via a self-actuating spring-type of manner whendeployed out of the fastener applicator into tissue. In either case,after extragastric insertion into stomach tissue, the proximal ends 1830of arms 1825 therefore preferably engage serosal tissue in directionsperpendicular to the plane of the fastener (i.e. pointing in a directionparallel to the approximated tissue interface), at locations away fromthe perforations made in the serosa by the penetrating tips 1820 duringfastener insertion. This unique out-of-plane tissue engagement featureprovides increased retention force and reduced chance the fastener willslip or tear out of the tissue as a result of tissue damage necessarilyincurred during fastener insertion. FIG. 18B shows another similarembodiment, where fastener 1850 consists of cross member 1855 and tissuepenetrating projections 1860 having sharpened tips 1865. In thisexample, tissue penetrating projections 1860 are positioned not at theends of cross member 1855 but rather at a position slightly medial, suchthat arms 1870 are positioned on the outside rather than the inside ofthe fastener. In this case, after extragastric insertion into stomachtissue, the proximal ends 1875 of arms 1870 therefore preferably engageserosal tissue not only out of the plane of the fastener, as describedfor fastener 1800 of FIG. 18A, but also at a position farther away fromthe approximated tissue interface, which may further increase retentionforce and reduce the chances of slipping or tearing.

As illustrated in FIG. 19, a fastener applicator 1900 according to oneembodiment of the present invention comprises a proximal handle assembly1902, longitudinal tube assembly 1904, and distal fastener deploymentassembly 1906 which is operably connected to handle assembly 1902. Tubeassembly 1904 is configured to allow device 1900 to be inserted into thecentral working channel of the tissue approximation devices of thepresent invention (e.g. working channel 826 of device 800 shown in FIG.8). The outer diameter of tube assembly 1904 is therefore preferablybetween 3 mm and 25 mm, more preferably between 4 mm and 18 mm, and mostpreferably between 5 mm and 15 mm.

The fastener applicator of the present invention may be designed todeploy one fastener (single fire instrument) or more than one fastener(multi-fire instrument) into tissue by propelling the fasteners out ofthe distal end of tube assembly 1904 and into target tissue at apredetermined speed and force. In a preferred embodiment, fastenerapplicator 1900 is a multi-fire device intended for single patient use,and is provided pre-loaded with a plurality of fasteners stored withintube assembly 1904. The speeds and forces at which fasteners arepropelled into tissue may be significantly greater than what istypically achieved using prior art fastener deployment mechanisms (e.g.hand powered deformable staples, helical or threaded fasteners, tackspushed directly into tissue, etc.). In this manner, the fastenerapplicators of the present invention provide more consistent andcontrolled fastener deployment and also overcome high tissue insertionforces to ensure complete fastener penetration and engagement within thetarget tissue. Propelling of fasteners is accomplished in fastenerapplicator 1900 using a unique spring loaded, impact driver-typemechanism described below.

A detailed cross section of handle assembly 1902 in the pre-firedposition is shown in FIG. 20A. To initiate an acutated firing cycle andthereby deploy a fastener into tissue, trigger 1910 is pulled by theoperator. Trigger spring 1912 causes trigger 1910 to return to itsoriginal position when released, after firing. Cocking bar 1914 isfixedly connected at its proximal end to trigger 1910 and at its distalend is configured to engage within groove 1916 of driver 1918. In thismanner, when trigger 1910 is pulled proximally by the operator, driver1918 is also moved proximally, compressing and thereby storing potentialmechanical energy in firing spring 1920. As trigger 1910 approaches itsproximal most position, release pin 1922 presses against cocking bar1914 causing it to elastically bend downward and thereby disengage fromgroove 1916. This releases driver 1918 and allows it to be propelledforward, thereby firing a fastener into tissue. The propelled forwardmotion of driver 1918 is powered by the release of mechanical energystored within firing spring 1920. Accordingly, the speed and force offiring are determined by the materials properties and dimensions, etc.,of firing spring 1920, which may be optimized to achieve various desiredfiring characteristics. In a preferred embodiment, the spring force maybe variably adjusted by the user (e.g. by turning a knob provided withinhandle assembly 1902, not shown) based upon the tissue characteristics,type of fastener, and so on. When driver 1918 is released and firing iscomplete, driver 1918 returns to its original pre-fired (distal most)position. Similarly, when trigger 1910 is released and returns to itsoriginal pre-fired position, cocking bar 1914 re-engages with groove1916 and the device is therefore readied for the next firing cycle.

According to one embodiment of the present invention, in this example amulti-fire device, distal fastener deployment assembly 1906 is shown inthe pre-fired position in FIG. 20B. Driver 1918 is slidably positionedwithin tube assembly 1904 and is configured having a reduced crosssectional area 1924 in its distal region. This provides space withintube assembly 1904 for fastener magazine 1926 within which a pluralitypre-loaded fasteners 1928 are stored in a stacked configuration. Eachtime the device is actuated, fasteners 1928 are sequentially advanceddistally, one position at a time, as a result of the force appliedagainst the stack of fasteners 1928 by magazine spring 1930 that pushesat its proximal end against spring stop 1932 which is fixedly mountedwithin tube assembly 1904. Prior to said actuation, the distal mostfastener in the magazine is in the loaded position 1934 and ready fordeployment. Retainer spring 1936 and retainer ball 1938 temporarily holdthe distal most fastener in the loaded position, providing a retentionforce against which magazine spring 1930 presses. Distal to the fastenerin the loaded position 1934 is firing channel 1940, through which theloaded fastener will be propelled when driver 1918 is released after theoperator fully actuates trigger 1910 in handle assembly 1902. Near itsdistal end, driver 1918 is configured with a flexible arm 1942,operation of which is explained below.

The details of operation of distal fastener deployment assembly 1906during a single firing sequence is illustrated in FIG. 21. In FIG. 21A,the device is in the pre-fired position, as described previously (i.e.FIG. 20B). In FIG. 21B, the device is shown in the configurationimmediately prior to the release of driver 1918, after trigger 1910 hasbeen pulled to nearly its proximal most position by the operator andfiring spring 1920 is fully compressed. During actuated retraction ofdriver 1918, flexible arm 1942 slides proximally and simultaneouslyelastically deforms into a flat configuration, allowing it to moveunderneath the stack of fasteners 1928 just until it's distal end passesbeyond the proximal face of the fastener in the loaded position 1934. Asillustrated in FIG. 21C, as soon as flexible arm 1942 moves proximal tothe fastener in the loaded position 1934, flexible arm 1942 deflectsupward, forcing the stack of fasteners proximally by compressingslightly magazine spring 1930 and thereby allowing the distal end offlexible arm 1942 to slide behind just the fastener in the loadedposition 1934. This individually separates the fastener to be deployed1944 from the remaining stack of fasteners 1928 and places the device ina ready-to-fire configuration. Upon release of driver 1918, actuated bythe final proximal motion of trigger 1910 by the operator, the forcesupplied by firing spring 1920 is transmitted through driver 1918 intothe fastener to be deployed 1944. By design, this force is sufficientlystrong to overcome the frictional force of retainer spring 1936 andretainer ball 1938 that holds fastener 1944 in position. Driver 1918moves distally and the fastener to be deployed 1944 is thereby propelleddistally 1946 through firing channel 1940 and out of the device withsubstantial force and speed. FIG. 21D shows the position of flexible arm1942 and the fastener to be deployed 1944 within firing channel 1940immediately after driver 1918 has been released. As shown in FIG. 21E,upon completion of the firing cycle, the fastener to be deployed 1944has been propelled from the distal end of tube assembly 1904 and driver1918 has returned to its original pre-fired position. The stack offasteners 1928 is 15 advanced by magazine spring 1930 to place the nextfastener in the loaded position 1934. When the operator then releasestrigger 1910 in handle assembly 1902 (FIG. 20A), trigger 1910 springsback to its original pre-fired position and cocking bar 1914 re-engageswith groove 1916 on the proximal end of driver 1918, and the device isready for another firing cycle.

FIG. 22 illustrates the combined use of tissue approximating devices ofthe present invention along with the fasteners and fastener applicatorsof the present invention, together comprising a system 2200 of thepresent invention, used for the purpose of carrying out the surgicalprocedure described previously. System 2200 comprises tissueapproximation device 202 having fastener applicator 2204 inserted intoits working channel. Although shown as separate devices in thisembodiment, it should be recognized by those skilled in the art thethese two devices, having substantially independent yet complementaryfunctions, may readily be combined into a single unitary device havingsubstantially the same features, actuation mechanisms and operationalcharacteristics. Such integrated multi-functional devices are consideredwithin the scope of the present invention.

In FIG. 22A, tissue approximation device 2202 IS designed and operatessubstantially similar to device 800 of FIG. 8, while fastener applicatordevice 2204 is designed and operates substantially similar to device1900 of FIG. 19. In this illustration, tissue approximation device 2202is shown in the deployed configuration with moveable arms 2206 extendingdistally from the device 2202 and having tissue hooks 2208 in positionready to engage tissue. The distal end 2210 of fastener applicator 2204has been pushed proximally out of the working channel of device 2202 andextends distally from the end of the device, such that when positionedabove and pushed against the extragastric surface 2212, tissueinvagination 2214 is formed, which is the first step in forming thedesired tissue fold.

FIG. 22B shows a close up illustration of the distal end of tissueapproximation device 2202 and fastener applicator 2204 after moveablearms 2206 have been pressed against the extragastric tissue surface 2212such that tissue hooks 2216 have engaged tissue at locations 2218 and2220. In this example, the distal end 2210 of fastener applicator 2204is still being used to push against the extragastric tissue surface 2212to ensure the desired tissue invagination continues, while tissueapproximation device 2202 is now ready to be retracted to create atissue fold, as described previously (see FIG. 12). Optionally, thedistal end 2210 of fastener applicator 2204 may preferably be usedduring this time to disrupt the thin layer of mesothelial cells coveringthe serosa and thereby promote a healing response, according to themethods of the present invention, as described previously. To secure thecreated tissue fold and produce a plication projecting into thegastrointestinal space, fastener applicator 2204 is retracted to aposition such that its distal end is placed in intimate contact with theapproximated tissue surfaces, substantially at the distal end of tissueapproximation device 2202. An alignment mechanism (described previously,refer to FIG. 14) is provided to ensure proper orientation of fastenerapplicator 2204 relative to tissue approximation device 2202. Thisensures that when the fastener applicator 2204 is fired and the fasteneris propelled into tissue (as described in FIG. 21), the fastener will beproperly positioned to reliably engage tissue on both sides of theapproximated tissue interface (as shown in FIG. 17).

FIG. 22C shows a close up illustration of the distal end of tissueapproximation device 2202 and fastener applicator 2204 being used onextragastric tissue surface 2212 to produce a plication projecting intothe gastrointestinal space, according to the methods of the presentinvention. In this example, four tissue approximation steps have beencompleted and extragastric tissue fasteners 2222 have been placed at thesite of each approximation step. Tissue approximation device 2202 isshown at a fifth location with moveable arms 2206 nearly fullyretracted, just prior to the firing of fastener applicator 2204 toinsert the next extragastric tissue fastener. In this manner the lengthof the plication may extended step by step, to create the necessaryplication and thereby achieve the intended stomach volume reduction, asdesired by the surgeon.

In other embodiments, described in detail below, the tissueapproximating devices of the present invention may optionallyincorporate operable means for articulating (i.e. rotating, deflectingor otherwise selectively moving and/or re-positioning) the distal end of10 the device relative to the position of the elongate tubular assembly.This functionality improves the surgeon's ability to quickly andefficiently engage and approximate the target tissue regardless of theangle of approach (which is dictated by the positioning of thelaparoscopic access port or trocar), and thereby not only speeds theprocedure but may allow the procedure to be performed using fewertrocars. In certain preferred embodiments, sufficient articulationfunctionality is provided in the device such that by appropriatelyplacing a single trocar through the abdominal wall the entire method ofthe present invention can be completed.

One embodiment of an articulating device is shown in FIG. 23, whichillustrates close up cross sectional views of the distal end of a devicewhich operates similarly to the devices described previously. In FIG.23A, which shows the device in the straight and retracted position,elongate tubular assembly 2305 is operatively connected to the distalarticulating tissue approximation assembly 2310 via pivot joint 2315.Articulating tissue approximation assembly 2310 has two moveable armsthat are joined at their proximal end creating a single moveable armassembly 2320 that is retractably held by pin 2322, fixedly attached tothe distal end of central cable 2324 passing through pivot joint 2315.Spring 2326 is compressed when moveable arm assembly 2320 is retractedinto distal tube 2328, which occurs when the user operatively actuatesthe handle assembly (not shown) to thereby pull proximally on centralcable 2324. When the user operatively releases tension on central cable2324, spring 2326 expands and moveable arm assembly 2320 thereby extendsout of the distal end of the device, as shown in FIG. 23B.

Arm tips 2330 and 2332, each having tissue engagement means 2334 and2336, respectively, are then placed in proper deployed position forengaging tissue, as described previously. After tissue is engaged, theuser again operatively actuates the handle assembly, thereby retractingmoveable arm assembly 2320 back into distal tube 2328 (FIG. 23A),effectively approximating the engaged tissue locations at a positionnear the distal end of the device.

FIGS. 23C and 23D illustrate the same retracted and deployedconfigurations, respectively, however in these examples, the device hasbeen operatively placed in an articulated position. Articulation iseffected by a controlled rotation of distal articulating tissueapproximation assembly 2310 around pivot joint 2315. To accomplish thisrotation, opposing steering cables 2334 and 2336, passing through pivotjoint 2315 and fixedly attached at the distal end of distal tube 2328,are operatively actuated from the handle assembly by the user. In theexample shown, steering cable 2334 has been pulled in tension(shortening it) while steering cable 2336 has been slidably released(lengthening it), and distal articulating tissue approximation assembly2310 has thereby been rotated downward by angle of deflection 2338. Theoriginal straight position may be restored and/or the direction ofrotation may be reversed simply by placing tension on steering cable2336 while slidably releasing steering cable 2334. A variety ofpivotable joint mechanisms known to those skilled in the art may be usedsuch as hinges, elbows, ball joints, universal joints, and the like.Using such pivotable joint mechanisms and two opposing steering cables,as shown in this example, deflection is generally limited to being up ordown within a single plane, and the maximum angle of deflection possibleis typically less than 90 degrees. When in an articulated position,actuation of moveable arm assembly 2320 to engage and approximate tissueis accomplished the same as described above (FIGS. 23A and 23B). In thismanner, the articulation function is therefore operatively controlledindependently from the actuation function.

Other embodiments incorporating operable means for articulating thedistal end of the device are illustrated in FIGS. 24 and 25. FIG. 24shows close up cross sectional views of the distal end of a device inthe straight and retracted configuration (FIG. 24A) and the articulatedand deployed configuration (FIG. 24B). In this embodiment, the pivotjoint has been replaced with a flexible member 2415 extending betweenelongate tubular assembly 2405 and distal articulating tissueapproximation assembly 2410. When used with more than two steeringcables 2420 (four cables are used in the embodiment of FIG. 24) that arerouted through cable channels 2425 and fixedly attached to distal tube2428, this device is capable of deflecting in any desired directionrelative to the positioning of the handle assembly. The actuationmechanism and tissue approximation steps involving moveable arm assembly2430, pin 2432, central cable 2434 and spring 2436 are substantiallysimilar to that described previously for device shown in FIG. 23. Theadvantages of this design are that the surgeon is provided with maximumfreedom by being able to deflect the distal articulating tissueapproximation assembly in any desired direction relative the position ofthe handle assembly.

FIG. 25 shows close up cross sectional views of the distal end of adevice in the straight and retracted configuration (FIG. 25A) and thearticulated and deployed configuration (FIG. 25B). In this example,which is similar to devices described previously, the distal end ofelongate tubular assembly 2505 is made from flexible material andprovides a protective covering for flexible member 2515 and steeringcables 2520, extending all the way to and connecting directly withdistal articulating tissue approximation assembly 2510. This providesfor a simpler, cleaner and safer articulating device configuration,while retaining all the advantages described previously.

According to another embodiment of the present invention, tissueretaining fastener 2600 is shown in the deployed configuration in FIG.26A and in the pre-deployed configuration in FIG. 26B. The fastenerconsists of a connecting member 2605 from which two or moreself-actuating, reconfigurable tissue penetrating members 2610 extend.Fastener 2600 is produced from a highly flexible material capable ofsubstantial elastic deformation, preferably a shape memory orsuperelastic material such as NiTi alloy or similar. Fastener 2600 maybe produced from wire, ribbon, sheet, bar stock, and the like.Connecting member 2605 may optionally include spring element 2615, whichcan be a coil spring, leaf spring, flexible hinge, and the like, thatmay be incorporated to increase the deployment and/or retention forcesof the fastener. Each of tissue penetrating members 2610 furtherincorporates a sharpened tip 2620 at its distal end, which arepreferably designed and configured to reduce the required tissueinsertion forces while simultaneously minimizing tissue damage. As shownin FIG. 26A, in the deployed configuration (i.e. the selfactuatingreconfigured shape after implantation in tissue) fastener 2600 forms aloop having largest dimension 2622 that at least substantially enclosestissue. A variety of shapes may be used to form the loop, such ascircular shapes, oval shapes, elliptical shapes, and so on. It isdesirable that, after deployment, sharpened tips 2620 are positioned soas not to pose a risk of irritating tissue or causing tissue damage. Inthe example shown, sharpened tips 2620 are designed to at leastpartially overlap one another.

In the pre-deployed configuration, fastener 2600 is held within asuitable fastener applicator (described below) in the shape illustratedin FIG. 26B. The deployment sequence is illustrated in FIG. 27. Bymechanically restraining fastener 2600 in the pre-deployed shape,elastic potential energy is stored in the reconfigurable tissuepenetrating members 2610 that provides a driving force (i.e. springbias) for the fastener to automatically return to the deployed shape(FIG. 26A). After being propelled forward 2705 into tissue 2710 byfiring of the applicator (not shown) to produce initial tissuepenetration (FIG. 27A), tissue penetrating members 2610 elasticallydeform in the proximal direction 2715 in a self actuating manner, (FIG.27B), thereby engaging and substantially enclosing tissue (FIG. 27C).One unique aspect of fastener 2600 is the substantially backward (i.e.proximal) direction of motion 2715 in which the distal endsself-actuating tissue penetrating members 2610 move duringreconfiguration to close the fastener, relative to the forward (i.e.distal) direction of motion 2705 of the fastener when penetratingtissue. In this reverse direction reconfiguration process, a loop shapedfastener is formed in the tissue (FIG. 27C), while having sharp tissuepenetrating tips 2620 that are positioned, after reconfiguration, nearor above the penetrated tissue surface.

For minimally invasive applications, fastener 2600 preferably has arelatively small width 2635 such that it can be held within the smallestpossible fastener applicator. Width 2635 is therefore preferably lessthan about 12 mm, more preferably less than about 8 mm and mostpreferably less than about 5 mm. The length 2640 of tissue penetratingmembers 2610 limits the final size of the loop formed by the deployedfastener. Length 2640 is preferably between 5 and 50 mm, more preferablybetween 8 and 30 mm, and most preferably between 10 and 20 mm. An uniqueaspect of this self-expanding and self-actuating fastener design is thatthe size of the loop 2622 in the final deployed configuration (FIG. 26A)can be substantially larger than the diameter of the fastener applicatorneeded to deploy said fasteners. For example, in one embodiment that hasbeen successfully tested, a fastener similar to fastener 2600 wasproduced from 0.38 mm diameter superelastic NiTi wire. The width 2635 ofthe fastener in the pre-deployed configuration was approximately 2.0 mm(easily deployed from a 5 mm applicator), the length 2640 of tissuepenetrating members 2610 was approximately 10 mm, and the final loopsize when deployed in tissue 2622 was approximately 7 mm. By engagingand enclosing a larger amount of tissue during fastener reconfiguration(FIG. 27), significantly increased tissue retention forces can beachieved using the smallest possible (i.e. a truly minimally invasive)delivery device.

During the use of a fastener such as fastener 1600 for the purpose ofextragastrically producing a plication by securing invaginated tissuefolds created by approximating stomach tissue, according to the methodsof the present invention, it is possible to place the fastener in eitherconfiguration shown in FIG. 28. In FIG. 28A, fastener 1600 is securingtissue fold 2805 created in gastrointestinal tissue layer 2810 bypenetrating the adjacent shoulders 2815 and 2820, respectively, thatwere created during tissue approximation. Note, the dimensions offastener 1600 are large relative to the thickness 2825 of tissue layer2810, and the fastener therefore has penetrated completely through thetissue. Complete penetration of fasteners though the tissue isacceptable practice in current gastric surgeries when using deformingbox-type staples of the prior art.

An alternative and preferred fastener configuration possible withfasteners of the present invention is shown in FIG. 28B. In this case,the dimensions of fastener 1600 are small relative to the thickness 2835of tissue layer 2840, and the fastener therefore has penetrated throughthe outermost (serosal) tissue layer and only partially through theunderlying muscularis tissue layers, avoiding full thickness throughpenetration of the tissue. Since most of the holding force for thefastener is provided by secure engagement with the thin yet toughserosal layer, this fastener configuration can be at least as strong asthat shown in FIG. 28A, while avoiding any possible complications thatmay result from perforation of the gastrointestinal tract or damage tothe internal (mucosal) layer involved in digestion. In fact, it isunexpectedly anticipated that the entirely extragastric fastenerplacement may be stronger than the full thickness through penetrationplacement since the muscularis and mucosal layers are inherentlyunstable with respect to retaining fasteners long-term. Fasteners may beplaced according to the configuration of FIG. 28A, FIG. 28B, andcombinations of the foregoing.

Detailed close up distal end views showing two different embodiments fordeploying fasteners 1600 into approximated tissue are shown in FIGS. 29Aand 29B, respectively. In FIG. 29A, outer tube 2920 and moveable arms2922 of a tissue approximation device as described previously are shown,with moveable arms positioned in a partially deployed configuration. Thedistal tube assembly 2925 of the fastener applicator device is showninserted into the working channel. One or more of fasteners 1600 areloaded into and constrained in the pre-deployed (spring-biased)configuration by applicator tube 2928. Pusher 2930 is operably connectedto the applicator hand assembly (not shown), and is configured to movedistally when the applicator hand assembly is actuated by the user. Whenin the ready-to-fire configuration, fastener 1600 is positioned justinside the distal end of applicator tube 2928, and pusher 2930 ispositioned and configured to apply a longitudinal force 2932 against theproximal end of fastener 1600 when actuated. When the applicator handleassembly is actuated by the user, pusher 2930 will force fastener 1600out of the distal end of the device, where it penetrates tissue andreconfigures in a self-actuating manner to securely engage andsubstantially enclose tissue, as described previously.

An alternative embodiment for distal tube assembly 2925 is shown in FIG.29B. In this case, deployment tube 2934 is slidably positioned insideapplicator tube 2928, and stores and retains fastener 1300 in thepre-deployed configuration. At the distal end of deployment tube 2934are insertion guides 2936 that are configured with sharpened tips 2938which are designed to penetrate tissue prior to deployment of fastener1600 when deployment tube 2934 is actuated by the user and thereby moveddistally out of applicator tube 2928. Insertion guides 2936 have asemicircular cross section designed to slidably engage the tissuepenetrating members 1610 of fastener 1600, as shown in the magnifiedcross section view A-A. In this manner, the tissue penetrating members1610 of fastener 1600 are retained in the pre-deployed configurationwhile insertion guides 2936 initially penetrate tissue to apredetermined depth, before firing the fastener. When fastener 1600 issubsequently forced out of the device by the actuated distal movement ofpusher 2930, the tissue penetrating members 1610 are released from theconstrained (pre-deployed) configuration only after first reaching aprescribed tissue depth. By controlling the depth of penetration of theinsertion guides 2936 prior to fastener deployment, relative to the sizeof the fastener, it is possible to ensure accurate and reproduciblefastener placement, resulting in optimal engagement and enclosing oftissue upon reconfiguration of fastener 1600. This will be illustratedand described in greater detail below.

Although the tissue approximation devices, tissue fasteners and fastenerapplicator devices comprising the systems of the present invention areillustrated above (e.g. FIG. 29) as being separate devices, it should berecognized by those skilled in the art the these devices, havingsubstantially independent yet complementary functions, may readily becombined and integrated into a single unitary device havingsubstantially the same features, actuation mechanisms and operationalcharacteristics. Accordingly, an example of such an integratedall-in-one device is illustrated in FIG. 30. FIG. 30A shows an overviewof device 3000, having proximal handle assembly 3002, longitudinal tubeassembly 3004 and distal tool assembly 3006, which incorporates bothtissue approximation and tissue fastening mechanisms and is operablyconnected to actuating mechanisms in handle assembly 3002. Handleassembly 3002 is provided with first actuating means 3008 used foractuating the tissue approximation mechanism and second actuating means3010 used for actuating the tissue fastening mechanism. Third actuatingmeans 3012 is optionally included and may be used to actuate theoptional serosal treatment mechanism. Rotating collar 3014 is providedto allow the longitudinal tube assembly to be oriented independentlyfrom the orientation of handle assembly 3002. A detailed close up viewof distal tool assembly 3006 positioned at the distal end oflongitudinal tube assembly 3004 is shown in FIG. 30B. Moveable arms 3020are shown in the deployed configuration, each having tissue engagementmeans 3022 positioned at its distal end. Fastener 3024 (substantiallysimilar to fastener 1600) is shown in the ready-to-fire position, beingrestrained in the pre-deployed (spring-biased) configuration by, andslidably within, insertion guides 3026.

The use of the above described devices and systems for carrying out thesurgical procedure of the present invention will now be described ingreater detail. FIG. 31 schematically illustrates the use of system3100. In FIG. 31, stomach tissue 3102 is shown, having exterior serosaltissue layer 3104, internal mucosal tissue layer 3106, with muscularistissue 3108 positioned between. After obtaining minimally invasivesurgical access to the stomach, a tissue fold is first created by theinitial actuated deployment (not shown) of moveable arms 3115 andsubsequent engagement of tissue at two separate locations (i.e. 3120 and3125) by tissue engagement means 3130. During actuated retraction ofmoveable arms 3115 back into device 3100, as illustrated in FIG. 31A,tissue locations 3120 and 3125 become approximated near the distal endof device 3100. In this manner, an invaginated tissue fold 3135 iscreated whereby intimate serosa-to-serosa contact area 3140 isestablished inside said tissue fold. Prior to or during the above tissueapproximation step, the tissue is optionally treated to promote ahealing response across the serosa-to-serosa interface. After tissueapproximation is completed, as illustrated in FIG. 31B, actuateddeployment of tissue fastener 3150 (substantially similar to fastener1300 of FIG. 13) occurs. In the example shown, the deployment mechanismis similar to that illustrated previously wherein deployment occurs as aresult of the forward (distal) motion of pusher 3152, during which eachof tissue penetrating members 3154 and 3156 penetrates tissue locations3120 and 3125, respectively, and fastener 3150 reconfigures in aself-actuating manner to its deployed configuration. Upon completion offastener deployment, as shown in FIG. 31C, fastener 3150 securelyengages the approximated tissue, producing plication 3160 projectinginto the gastrointestinal space. While complete penetration isacceptable, in the example shown, fastener 3150 penetrates and engagesonly serosal tissue layer 3104 and muscularis tissue 3108, withoutpenetrating completely through the gut wall or otherwise disruptingmucosal tissue layer 3106. A strong serosa-to-serosa bond will formacross contact area 3140 after approximately 7 days beyond surgery,thereby ensuring long-term durability to plication 3160.

FIG. 32 illustrates substantially the same tissue and deviceconfigurations and operational sequence as in FIG. 31, however in theexample of system 3200, the fastener deployment mechanism issubstantially similar to that shown previously in FIG. 29B. Accordingly,in FIG. 32B, prior to the forward (distal) motion of pusher 3205 todeploy the fastener 3210 into tissue, insertion guides 3215 and 3220 arefirst extended distally from the end of the device, thereby penetratingtissue to a pre-determined depth, followed by the subsequent deploymentof penetrating members 3225 and 3230. In this manner, the selfactuatingreconfiguration of fastener 3210 is further controlled and optimized,producing more accurate and repeatable tissue engagement (FIG. 32C).

An alternative embodiment of a fastener of the present invention isillustrated in FIG. 33. Fastener 3300 is a self-actuating, backward(proximal direction) forming flexible-type fastener substantiallysimilar to fastener 1600 (FIG. 16). However, the shape in the deployedconfiguration (FIG. 33A) has been modified to more effectively engageand securely hold the approximated tissue of the created tissue fold. Asshown in FIG. 33A, each of the reconfigurable tissue penetrating members3305 and 3310 forms a substantially closed loop on itself, withsharpened tips 3315 and 3320, respectively, positioned close to theproximal end of the penetrating members. Optional spring element 3330positioned between the penetrating members may be used to provideadditional force and/or holding strength to the fastener.

As shown in FIG. 34, the deployment sequence for fastener 3300 issubstantially similar to that shown previously. By mechanicallyrestraining fastener 3300 in the predeployed shape, elastic potentialenergy is stored in the reconfigurable tissue penetrating members 3305and 3310 that provides a driving force (i.e. spring bias) for thefastener to automatically return to the deployed shape (FIG. 33A). Afterbeing propelled forward 3402 into tissue 3404 by firing of theapplicator (not shown) to produce initial tissue penetration, tissuepenetrating members 3305 and 3310 elastically deform in the proximaldirection 3406 in a self actuating manner, (FIG. 34B), thereby engagingand substantially enclosing tissue (FIG. 34C). Similar to fastener 1600,a unique aspect of fastener 3300 is the substantially backward (i.e.proximal) direction of motion 3406 in which the distal endsself-actuating tissue penetrating members 3305 and 3310 move duringreconfiguration to close the fastener, relative to the forward (i.e.distal) direction of motion 3402 of the fastener when penetratingtissue. In this reverse direction reconfiguration process, each tissuepenetrating member independently forms a substantially closed loop inthe tissue (FIG. 34C), while having sharp tissue penetrating tips 3315and 3320 that are positioned, after reconfiguration, in such a manner soas not to produce tissue irritation or damage after fastener placement.Another unique aspect of this fastener that improves its holdingstrength when placed extragastrically in stomach tissue can be observedin FIG. 34C. Note that during reconfiguration the fastener actuallypasses through the thin, tough external serosal tissue layer 3410 two ormore times (three times in the example shown), resulting insignificantly greater holding force for the deployed fastener.

FIG. 35 illustrates the use of fastener 3300, along with integrateddevice system 3500, for the surgical method of the present invention.The tissue and device configurations and operational sequence aresubstantially similar to that described previously. Pusher 3505 propelsfastener 3300 out of the distal end of the device, after insertionguides 3515 and 3520 have penetrated tissue. This allows tissuepenetrating members 2205 and 2210 to reconfigure in a self-actuatingmanner, thereby accurately and controllably engaging and securing thetissue fold 2035 to produce a plication 2060 projecting into thegastrointestinal space. In the example shown, a completely extragastricfastener placement is shown, and a strong serosato-serosa bond will formacross contact area 2040 after 7 days beyond surgery, thereby ensuringlong-term durability of plication 2060.

We claim:
 1. A method for manipulating tissue, comprising: accessing anexternal surface of a wall of the gastrointestinal tract; engaging atleast two tissue sites spaced apart from one another on the externalsurface of the wall of the gastrointestinal tract, thereby providing atleast two engaged tissue sites; manipulating each of the at least twoengaged tissue sites to form a tissue shoulder at each engaged tissuesite; approximating the tissue shoulders toward one another and movingthe tissue shoulders in proximity to one another to form a tissue foldextending into an internal gastric space; and securing the tissueshoulders to one another by applying a tissue fastener, thereby securingthe tissue fold.
 2. The method according to claim 1 wherein the tissuefastener is selected from the group consisting of sutures, staples,screws, tacks, clips, hooks, clamps and t-tags.
 3. The method accordingto claim 1, wherein the steps of engaging, manipulating, approximatingand securing are repeated a plurality of times to extend a dimension ofthe tissue fold, wherein the dimension is selected from the groupconsisting of a length dimension and a depth dimension.
 4. The method ofclaim 1, wherein an interior surface of the wall of the gastrointestinaltract is not contacted or penetrated during the steps of engaging,manipulating, approximating and securing tissue.
 5. A device forengaging, approximating and fastening tissue comprising: tool assemblyadapted for insertion into a body cavity and having at least twoextendible members adjustable between a pre-deployed, insertioncondition and a deployed extended condition, each of the extendiblemembers comprising at least one associated tissue engagement mechanismfor securely engaging tissue; an actuating mechanism adapted forreversibly positioning at least one of the two tissue engagementmechanisms spaced apart from another tissue engagement mechanism; anintegrated tool configured to deploy a plurality of tissue retainingfasteners sequentially for fastening engaged and approximated tissue;and a plurality of tissue retaining fasteners retained in the device. 6.The device according to claim 5, additionally comprising a cartridgeloaded with the plurality of fasteners and a mechanism for feedingfasteners from the cartridge to the integrated tool.
 7. The deviceaccording to claim 5, additionally comprising a proximal handleassembly, wherein the actuating mechanism adapted is located on thehandle assembly, and the handle assembly additionally comprises afastener deployment actuating mechanism adapted to deploy the tissueretaining fasteners.
 8. The device according to claim 5, wherein theactuating mechanism is adapted for reversibly positioning at least twotissue engagement mechanisms.
 9. The device according to claim 5,wherein the tissue engagement mechanisms are selected from the groupconsisting of hooks, barbs, grippers, teeth, clamps, jaws, clips, andt-tags.
 10. The device of claim 5, additionally incorporating aselection feature allowing user-selection of a distance of separationbetween the tissue engagement mechanisms when the extendible members arein the deployed extended condition.
 11. The device of claim 5,additionally comprising a mechanism for releasably holding the at leasttwo extendible members in the pre-deployed, insertion condition.
 12. Adevice of claim 5, wherein at least one extendible member is configuredto provide user control of directions and magnitudes of forces generatedon the tissue during deployment and/or retraction of the device.
 13. Adevice according to claim 5, wherein the extendible members aresubstantially rigid, or are flexible, or have both substantially rigidand flexible portions.
 14. A device of claim 5, wherein the tissueretaining fasteners are deformable staples, and the integrated toolcomprises a mechanism for feeding, forming and releasing the staples.15. A method for forming and securing a fold in tissue comprising:accessing a tissue surface with a device for engaging, approximating andfastening tissue; engaging at least two spaced apart tissue sites on thetissue surface; manipulating the at least two spaced apart tissue sitesto form tissue shoulders at each of the spaced apart tissue sites;approximating the tissue shoulders to form an invaginated tissue foldextending away from the distal end of the device; and fastening tissuein proximity to the approximated tissue shoulders to secure the tissuefold.
 16. A method of claim 15, wherein approximating the tissueshoulders is accomplished through a combination of motions selected fromthe group consisting of pushing motions, pulling motions, twistingmotions and shearing motions.
 17. A method of claim 15, additionallycomprising treating the tissue surface to promote bonding between theapproximated tissue shoulders.
 18. A method of claim 15, whereinapproximating the tissue shoulders to form the invaginated tissue foldextending away from the distal end of the device involves a combinationof pulling the tissue shoulders toward the distal end of the devicewhile simultaneously pushing the tissue surface between the tissueshoulders away from the distal end of the device.
 19. A method of claim15, wherein the tissue surface is an external surface of the wall of thestomach, and the tissue fold reduces the volume of the stomach by atleast 20%.
 20. A method of claim 15, wherein the depth of the tissuefold is increased by repeating the recited operational steps on thetissue surface in order to approximate and secure a second set of tissueshoulders over the top of the previously secured tissue fold.